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The Starter’s Guide to Using Cold Frame in Gardening

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Imagine if you can have a fresh green salad in February or some juicy red tomatoes in November. Sounds like a dream doesn’t it? Maybe you’ve heard of it. Maybe you’ve seen it. Maybe… it’s cold frame gardening.

Yes. All of this can happen in your very own garden. And you don’t even need a lot of space for this. So for your convenience, we have gathered the most important and basic info you will need about cold frame gardening.

Table of Contents

What is cold frame gardening

Cold frame gardening is a form of planting different types of green life in an enclosed environment with the aim of extending the growing season of the plants. Building a cold frame is not a hard task. All you need is to make a wooden panel frame from an old glass window and put the glass over the frame. The glass roof should be oriented towards the sun in order to capture as much light as possible. If you do not have glass you can use a thick transparent plastic sheet.

How cold frames work

The whole idea of the cold frame’s structure is to protect the plants from the harsh conditions of late autumn, winter, and early spring. It shelters the green life from snow, rain, strong winds, hail and ice. Thanks to the window roof it also collects sunlight and warmth, keeping them inside the frame for a longer time. A cold frame structure usually keeps a difference of 5 to 10 degrees between the inside and outside environment.

You place the seeds inside the frame and they grow into plants, resistant to the cold weather. Still, the collected heat needs to escape in order not to fry out your crops. The best thing you can do is to install a vent with a closing mechanism. Opening it every two days would be enough.

Advantages and disadvantages of cold-frames

Benefits

  • Can be used when you don’t have enough space for a greenhouse;
  • You would love to have an early start on the outdoor growing season or extend your crops’ life after the summer is over;
  • You can use it to protect dormant plants until spring comes;
  • Cheaper than a greenhouse;
  • You want a mobile solution for growing plants in winter;
  • You can build two types of cold-frames (brighter or shadier spots can help raise different plants – e.g. vegetables or cuttings).
  • You can design your cold frame according to your own needs. There are no limits when constructing one so you can use your full imagination.

Disadvantages

  • It falls behind glasshouse or a polytunnel because they give you the option to actually walk in and manage the growing conditions;
  • There’s less volume of air and there’s no buffer that will negate the effects from temperature amplitudes;
  • Humidity is also a more severe problem due to the less air in cold-frames rather than in polytunnels or greenhouses;
  • It keeps the soil dry so you need to have a very strict schedule of watering the crops;

How to use a cold-frame

Cold frames during Spring

The cold frame is perfect if you want to harden young plants. To harden them means to acclimatise them to harsher weather conditions, higher or lower humidity and increased air movement before it’s time to plant them outside. The cold frame will serve as the middle stage when you are transferring the plants from inside your house to the garden. The frame is a controlled environment so you can use it however you need.

Cold frames during Summer

Using the cold frame in the summer allows you to provide certain plants with more heat before the season actually starts. This is very useful when planting, for example, tomatoes and chillies. The increased warmth from the cold frame will encourage and speed up their growth.

Another use for it during Summer will be propagating plants. No surprise heat waves or rainy days will be able to interrupt your gardening plans when you are using the cold frame. You can start from seeds, semi-ripe cuttings or young plants and adjust the conditions according to the needs of your crops.

Cold frames in Autumn

In the Autumn cold frames will protect the young plants and cuttings from unpredicted weather conditions like early snow or night frosts. You will also be able to extend your harvest season with at least 4 weeks.

Cold frames in Winter

You can use your cold frame in winter to prevent alpines from rotting by shielding them from the rain and snow. You can overwinter the fresh annuals and keep them until spring comes. If you want to add some extra protection, you can place a layer of bubble plastic on the inside. It will protect the plants from frosts but it will reduce the light and ventilation as well.

Cold-frames vs mini-greenhouses

Greenhouses are a lot more popular in gardening than the cold frames. Due to the harsh weather for most of the year in the UK, there are many plants and crops that are only able to grow in greenhouse conditions and would never survive outside. Most growers turn to cold frames only because of the size factor but actually, there are many other differences you must take in the count before going for one or the other.

What are greenhouses

The construction of a greenhouse is a fairly easy, similar to a cold frame. They are usually made of glass that is supported by either a wooden or an aluminium frame. The size depends on the crops you will be planting and how much space they would need to grow big and strong.

The main function of a greenhouse is to allow the outside heat to enter but not to let it leave. And that is where the term “greenhouse effect” comes from. If you need to raise the temperature, even more, you can use a heater. This way you will create a perfect environment for plants which would need a lot more warmth to grow. They will be sheltered from the rain and wind. The structure of the greenhouse allows multi-level planting of crops and also there will be enough space for your garden tools. If you do not have enough space in your garden for a full-size greenhouse you can try and build a custom one which is smaller. But a lot of the main functions will be lost. You will not be able to walk around and no extra heat can be provided if it’s needed. So a full-size greenhouse is always the best option.

Cold frames can offer you most of the advantages you can get from a greenhouse. But let’s take a look now at the main differences which will determine your choice in the end.

You will get the same warming effects from a cold frame as a greenhouse but without the option to use an extra heater when the weather is too cold. There is simply not enough space to do so. Cold frames are not suitable for the whole life cycle of a plant. It can only extend the harvest period or give the green life an early start.

The space inside is very limited. In addition to their small size, cold frames are usually built very low so you cannot use racks and you wouldn’t have any floor space. Cold frames can be designed as per all your special gardening needs.

At first glance it may look like cold frames are just the smaller versions of greenhouses, even inferior sometimes. But bear in mind that they are specially designed for different purposes such as germinating, something you cannot do in a greenhouse. They are also perfect for small gardens and people who do not have the resources or the need to maintain a whole greenhouse. It’s cheap to buy, easy to build, easy to maintain and will fit perfectly no matter how small your garden is.

Tips on how to do successful cold-frame gardening

How to pick the perfect site for your cold frame

The whole idea of the structure is to gather sunlight and warmth so the best position for a cold frame will be one that offers full sunshine and will shelter your plants. The frame has to face the south. With these conditions in mind, you can put it pretty much anywhere – against a shed, garage, greenhouse, your house or a deck. If you need the cold frame mostly for growing cuttings, it would be better to put it someplace shady.

How to pick the right cold-frame material

One of the many great things about cold frames is that you can build them from almost anything. The main idea is to have a solid material for the sides and a glass, or anything transparent, for the top. Most people use wood, but you can do it with bricks, polycarbonate, straw bales, PVC, blocks, and many more. It only needs to be solid and strong so it will protect your crops from the harshest winds. The lid can be a glass door or a window. If you cannot get one, simply take a sheet of glass or polycarbonate and secure it to a wooden frame. Don’t forget that you are constructing it as per your needs so if you need you can add handles.

How to capture more heat in your cold-frame

There are many ways you can trick that rare UK sunlight into staying a bit more in the cold frame and keep it warm. Paint the inside of the frame in white or cover it with aluminium foil. It will reflect the sun rays all day, ensuring enough sunlight. Another thing you can do, is to take a couple of water jugs and paint them black. Fill them up and place them inside the frame during the day so they will gather heat. The jugs will release warmth throughout the whole night.

How to keep your cold frame clean

Regular maintenance is very important in order for the cold frame to work. In autumn you will have to clean it every 2 days at least from the fallen leaves and branches. During winter time, clean the built-up snow on the lid by using a sturdy push broom. The main idea is to get rid of everything that might block the light from reaching your crops in the cold frame.

Here are the top winter cold-frame crops

Of course, not every plant will thrive in such conditions so if you are wondering what to grow in a cold frame, here is a list of the most common crops you can take care of:

  • Arugula
  • Tomatoes
  • Broccoli
  • Beets
  • Cabbage
  • Carrots
  • Chard
  • Chinese cabbage
  • Green onion
  • Kale
  • Lettuce
  • Mustard
  • Radish
  • Spinach

Cold-frame alternatives that you can resort to

If you do not have the material or space for a cold frame or a greenhouse, don’t worry. Smart people way before our time thought up a couple of alternatives that are even easier to make and use.

For individual plants and crops, you can cut a plastic bottle and put it over the plant or the seedlings. You cut down the bottom of the bottle and don’t take the cap off.

Larger areas of plants can be covered by old window glass and panes raised on bricks or resting on sides of wood. Even though they will not have the exact same effect as a cold frame it’s a good, cheap and quick alternative for your garden.

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So here are all the basics you will need if you decide to try building and using a cold frame for your crops. Have you ever tried cold frame gardening? What are your favourite plants to grow there? Write about your experience in the comments down below and if you liked the article don’t forget to share it with your friends and family!

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Garden With Cold Frames to Grow More Food

After seeds have begun to grow inside the frames, the plants are surprisingly cold tolerant. I have watched lettuce seedlings sail through 10-degree nights when the frame was covered with a thick polyester-filled blanket, and framed-up spinach never sulks no matter how cold it gets. Yet these and other winter-sown vegetables will complain if a frame is allowed to overheat, so it’s crucial that frames be opened to vent out excess heat. When in doubt, it is always better to vent than to risk frying your plants. If you can’t be around to open and close your frame and a warm sunny day is in the forecast, covering the top of a closed frame with a light-blocking blanket for a few days is your safest strategy. If blustery winds threaten to sabotage your venting plan, place a board over the box, between the frame and the top, to keep it from slamming shut. Or use hooks and eyes to fasten the open top to posts sunk into the ground alongside the frame.

Climate-Controlled Frames

Any cold frame will harness solar energy for your plants’ benefit, and there are several low-tech ways to help your frames retain solar warmth. Black antifreeze containers, milk or kitty litter jugs painted flat black can be filled with water and tucked into the corners. Or you can cover the spaces between plants with flat stones painted black or “solar pillows” — used freezer bags painted black and filled with water. If you want to get more sophisticated, check into the Solar Pods and Solar Cones developed by New Hampshire gardeners Leandre and Gretchen Poisson. Described in detail in their book, Solar Gardening, and in MOTHER’s online Archive, the Poissons’ devices are probably the best you can build, if you can afford the materials. The superior performance of these garden appliances comes from the use of Sun-Lite flexible fiberglass, which costs about $80 for a 4-by-8-foot piece.

Historically, gardeners have used the warmth generated by rotting manure to turn cold frames into hot beds. To make a hot bed, dig a hole inside your frame at least 12 inches deep and fill it with fresh horse manure mixed with straw, and topped with 6 inches of soil. As the manure decomposes, it releases heat into the frame.

But you don’t have to have fresh manure to build a hot bed — or at least a warm one. For example, let’s say you want to winter-sow broccoli, spinach or another crop that needs abundant nutrients. If you dig out a bed and refill it halfway with compost mixed with the cheapest dry dog food you can find (a sure-fire compost activator), and then top it with 6 inches of soil, the compost will generate enough heat to keep the little plants from freezing and thawing quickly — if they freeze at all. In spring, when the plants’ roots find the buried treasure deepin the bed, you may be looking at the biggest, best plants you have ever grown.

Another option is to use the warmth generated by rotting hay to heat your cold frame from the sides. If you have plenty of space available and you plan to mulch with hay or straw this season anyway, go ahead and get four bales and arrange them in a semicircle on ready-to-plant ground, with the open side facing south. Plant the middle, and then top the bales with a wide sheet of plastic stapled to two 2-by-4s; one board will lie atop the back bales, and the other will anchor the plastic to the ground in front. You can make a bigger hay bale haven by arranging seven or eight bales in a square, and topping the enclosure with an old window, glass door or piece of sheet vinyl or corrugated fiberglass. Or, make your bales go twice as far by breaking them in half and encircling your planting with half bales, set side by side with their cut sides out. Allow the broken bales to get nice and damp before you plant, and then cover the bed and bales with a large piece of plastic sheeting. As the wet hay decomposes, much of the heat it releases will stay inside the bed.

To prepare a hot bed, warm bed or solar-charged cold frame when the soil is frozen, simply place a closed frame over the spot for several days. Daytime heating will thaw the soil inside, an inch or two at a time.

Various types of cold frames are multiplying like rabbits in my garden. With the help of the frames, spring now comes to my garden at least six weeks ahead of schedule.

Top 12 Winter Cold Frame Crops

These 12 vegetables are easy to grow when sown in cold frames in late winter. (For tips and tricks to growing these vegetables, click on the name to access the growing guide.)

• Arugula
• Broccoli
• Beets
• Cabbage
• Chard
• Chinese cabbage
• Green onion
• Kale
• Lettuce
• Mustard
• Radish
• Spinach

Mini Cold Frames: Milk Jug Seed Starters

This simple technique was developed for seeds that need to spend a winter outside before they will germinate, but it’s also a great method to start garden seeds in late winter if you don’t have indoor lights or a cold frame.

• Cut a gallon milk jug (or other large plastic container) in half horizontally, leaving one edge intact to use as a hinge. Discard the cap.

• Punch several drainage holes in the bottom.

• Fill the bottom with 3 inches of potting soil, moisten well and plant your seeds.

• Fold down the top cover, and secure the cut seam with duct tape. Enclose the planted jug in a large clear or opaque plastic bag (such as a produce bag), held together at the top with a twist tie.

• Place in a sunny, protected spot outdoors.

• One week before transplanting, harden off seedlings by removing the bag and tape, and propping the jug open with clothespins.

Anatomy of a Cold Frame

Site Surface: Frames work best if the top is angled slightly toward the winter sun. You can either cut slanted sides (see illustration, Image Gallery) or, as an alternative, mound soil as needed to make the back edge of the frame sit slightly higher than the front.

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Frame: Scrap wood or untreated 2-by-4 or 2-by-6 pine boards are fine, or you can upgrade to rot-resistant cedar, redwood or locust or composite plastic lumber. Other options include logs, baled hay or straw, bricks or concrete blocks.

Corners: If you only have a hand saw, a hammer and a screwdriver, you can build a sturdy box from 2-by-4s, a few screws and four steel corner brackets. Brackets come in different forms — some for inside the box and some for outside. The simplest (and cheapest) ones screw into the top of a frame that’s already been banged together with 3-inch box nails.

Covers: The best materials for topping cold frames are tempered glass patio doors or shower doors, which often are discarded when homes and apartments are remodeled. Heavy enough to resist strong winds, shatter-resistant tempered glass doors are better scavenger hunt treasures than standard storm windows or paned windows, which can be a safety hazard. Look in thrift stores (Habitat for Humanity often sells donated doors), or call people in home remodeling or salvage businesses. Look for doors that still have plenty of hardware attached, and leave the hardware intact as you scrub down your prize. Later, after you’ve built a frame, the existing hardware may prove handy as part of a nifty hinge or a ready-made handle. Tempered glass doors come in all sorts of weird sizes, so it’s best to secure a top first, and then tailor the frame to match its dimensions.

Use thick blankets, quilts or bedspreads to bring winter-sown frames through winter storms, or to block sun when you can’t be around to vent the frames. Snow makes a good insulating cover, too.

Focus On: Using a Cold Frame

What is a Cold Frame?

Cold Frames have been used for hundreds of years by both vegetable and ornamental gardeners for a host of gardening needs. Once gardeners start using a cold frame, they don’t know how they ever did without it. It is an essential component of successful gardening, or gardening made easy.

A cold frame is, in essence, a protected bed that will provide you with a shelter during cold temperatures that protects young plants in both spring and fall. Cold frames have no moving parts or electrical components: They rely on heat generated by solar energy, in which the sun’s warmth is absorbed by the soil within the cold frame and then released slowly as the temperature drops. Cold frames provide a few degrees of warmth while keeping frost off tender plants prior to their transplant to the garden, which is critical to gardening success.

What types of plants are best grown in a Cold Frame?

The cold frame is an exceptional transitional structure from indoor to outdoor gardening. Its number one use is for acclimating indoor-sown seedlings to the outdoors, by providing protection against frost and allowing the seedling to adjust to cooler outdoor conditions and natural sunlight. Seedlings grown in a cold frame will not be shocked when permanently planted; they will grow uninterrupted, which equates to earlier harvests and higher yields.

Gardeners have had much success using a cold frame for tomatoes, peppers, and all vine crops, such as squash, cucumbers and melons. Gardeners also use them for all the popular flower varieties such as zinnias, sunflowers, petunias and impatiens, just to name a few.

Many gardeners use cold frames as a method of production for cool season vegetables. Nearly all salad greens such as lettuce, spinach, arugula and mesclun can be direct sown up to a month earlier in a cold frame, bringing your favorite healthy leafy greens to a much earlier harvest. In the fall, a cold frame can protect these same leafy greens for up to a month from cold weather, again providing extended harvest. Between spring and fall, you can easily extend your garden harvest by 60 days.

Cold frames can be used to overwinter your harvested root crops. Root crops can be healed into the soil for easy digging on warm, sunny winter days. Potatoes, onions and carrots store exceptionally well in the cold frame. Tender bulbs dug from the garden and non-hardy perennials can be overwintered as well, so you will not have to buy those bulbs or plants every spring.

What is involved in operating a cold frame?

When you situate the cold frame, it needs to face south so the sun’s rays enter the cold frame as long as possible during the day. The cold frame needs to be located in a very well drained location with no standing water at any time. Providing a 2-4” layer of sand or gravel will enhance drainage. Inside the cold frame, use high-quality, well composted compost or purchased potting soils, free from weed seeds.

Ideally, butt the cold frame up against a structure that will block the wind, or use bales of straw to create a northern windscreen. Do not allow the windbreak to shade the cold frame. Not all cold frames are above the soil: Many of the historic cold frames were below the soil line, which allowed for even more protection and took advantage of the heat given off by the earth.

Ventilation is very important. During a bright sunny day, the temperature inside the cold frame will build. A slight opening of 2-4” will provide ample ventilation to allow the excess heat to escape, but will still protect your cold frame contents. Ventilation will also prevent condensation from forming and dripping water onto the contents. In a very short amount of time, you’ll understand the simple needs of the cold frame, which is basically adjusting the doors based on the anticipated weather.

Want to know more?

Most gardeners start with 1 or 2 Cold Frames, learn the operational requirements, and install additional ones as their gardening needs increase. Some gardeners use cold frames as a large seed-starting bed. Many vegetables and flowers can be direct sown into a cold frame and transplanted very successfully to the garden. During extreme cold in spring or late fall, a blanket can be placed over the cold frame in the evening for additional insulation. When training in the use of your cold frames, a high-low thermometer is very useful to see the temperature fluctuations. The thermometer will help in managing the ventilation timing. When watering inside a cold frame, morning watering is best to allow for the leaves to dry during the day. In Zone 6, spinach has been grown all winter in a cold frame. Cold frames are also a great place to store your recently delivered plants: Gardeners often use them when they receive their orders from catalog shopping.

Learn how to make a cold frame for the garden with these tips. When those first frosts of fall hit, you’ll want to protect your precious plants!

What are Cold Frames?

At their simplest, cold frames are bottomless boxes that are set over plants in the garden to protect them from adverse weather. They are usually built low to the ground and have a transparent roof to let in light and a hinge for easy access.

Why Use a Cold Frame?

Cold frames protect plants from strong winds and retain heat. Gardeners use cold frames to extend their gardening season—both in the autumn to protect plants for a few more weeks and in the spring to get a jumpstart on sowing seeds. Cold frames are also used to “harden off” seedlings that were started indoors.

  • Try sowing seeds of crops such as radish, lettuce, endive, and scallions directly in the frame for an early or late harvest.
  • You can even raise them there all summer as long as the cover is removed when warm weather arrives.
  • Consider growing winter lettuces or other salad greens, like spinach or kale.

How to Make a Cold Frame

Cold frames can be bought or constructed from timber and plastic, but concrete blocks or bricks can also be used. You can even construct a simple, bottomless wooden box and set it in the garden or atop other good soil in a sunny location. Watch our video, below, for step-by-step building instructions!

Cold Frame Building Tips

  • Most gardeners use wood to build the frame, since it’s readily available and is easy to cut to the required size using hand tools. If you’re lucky enough to find scraps of hardwood, then use this, as it will last longer than softwood.
  • Avoid old wood that’s been treated with creosote or similar non-earth-friendly products, especially if you’ll be positioning the cold frame directly on the soil. The wood can always be painted with a non-toxic paint if you’re worried about it looking scruffy.
  • Top the box either with glass (perhaps an old storm window) or a frame covered with clear plastic. Thicker materials will provide more insulation, of course. Old windows and shower doors are classic subjects for this project. Hinge the cover or add a sliding lid so that it may be opened for ventilation on warm days.
  • If you have high-sided raised beds, you could add a sheet of glass on top to construct a temporary cold frame.
  • Temporary frames or “cloches” can also be made by leaning old storm windows tent-style over the plants along the length of the garden row.
  • For those of us with limited time and/or DIY skills, try cutting the bottoms out of plastic milk jugs and placing them over individual plants, holding the jugs in place with mounded soil. During sunny days, remove the caps for ventilation.

How to Make a Hot Bed

A hot bed is a cold frame that is heated. Some gardeners use electric heating tape or cables, but the age-old method of using horse manure or compost works well, too.

  • For a nonelectric hot bed, excavate 18 to 24 inches under the frame and add fresh manure or compost.
  • Turn and moisten this material every couple of days for a week until it settles, then cover it with 6 inches of soil.
  • As the manure or compost decomposes, it will generate enough heat to protect against early or late frosts.

See our video with step-by-step instructions on how to build a cold frame.

Do you use a cold frame or hot bed in your garden? Share your technique in the comments below!

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Cold frames are a great season extension tool to help you garden in cold weather or to start warm weather seedlings long before your last frost date. Learn all about cold frames (including DIY cold frames) in this article!

Cold frames: a useful resource for cool and cold-weather gardening

Have you ever tried to start seeds indoors and ended up with anemic, gravity challenged sprigs? Bright, direct light is vital to emerging seeds and most windowsills are not sunny enough.

This leaves you with two options:

  1. indoor grow lights (like the DIY grow light system we recommend), or
  2. real sunlight with cold protection.

Artificial lighting (grow lights) is an ideal choice if you have the indoor space. If your indoor space is at a premium but you want to start garden seedlings to get a jump start on the growing season, cold frames are your best bet.

Thankfully, cold frames are also easy and inexpensive to build!

Not everyone has a greenhouse like this. Cold frames are a more frugal option for both money and space.

What is a cold frame?

A cold frame is exactly what it sounds like: a transparent outdoor frame that protects plants from cold weather while still letting sunlight in.

This means your plants get natural sunlight and extra warmth. In most regions, a cold frame can be used effectively to grow winter seedlings and crops, though if you live in a climate zone below USDA Zone 6, you may need a more fortified version than the one I use in my garden.

A cold frame can be constructed from materials you can easily find. This one, photographed in Asheville NC (zone 7a/6b), is made from lumber and some old windows. Notice the rocks around the cold frame as well, which trap heat, helping to create a warmer microclimate.

Also, if you don’t feel like making your own cold frame, you can order a really good Austrian/German-designed cold frame via Amazon. It’s double sided (more space), made of durable materials, lets in light from all angles, and you probably couldn’t make it more affordably if you were to buy all the pieces/parts yourself.

How to make cold frames

Cold frames are typically unheated. All their plant-protecting power comes from solar energy stored in the structure and soil during the day.

Parts of a cold frame:

Top – A light-permeable cover such as glass, plexiglass, or greenhouse plastic is used for the top of a cold frame.

Sides – The sides are made of any material that will create a supportive structure for the cover.

Bottom – A bottom is not necessary for your cold frame. Most people just use soil. If you decide to create a base for your cold frame, make sure it allows water to drain.

Our cold frame constructed from straw bales and recycled windows.

We used recycled windows for our cold frame. Some of them came from a friend’s farm, some of them came from my husband’s coworker, and some of them came from our local Habitat for Humanity store.

Glass is the most transparent and permanent material you can use… unless you live next to children playing ball or position your cold frame under the Whomping Willow (or any aging tree).

Depending on how cold your weather gets you may want the straw bale joints on your cold frame to overlap more. In very cold areas be sure to stuff any gaps with loose straw or leaves.

Available materials and permanence: considerations when constructing your cold frame

Straw has been our material of choice for the sides of our cold frame. Why? Straw bales are:

  • thick and very insulating,
  • easy to come by (garden, home improvement, and farm stores all carry them),
  • relatively inexpensive (in bad hay years the price goes up),
  • fully biodegradable when we are finished with them,
  • extremely easy to assemble.

At this point we’ve been using straw for 3 years and have found it perfectly suited for our needs. I had given up on shelf greenhouses or ever getting around to building a wooden cold frame and was carrying my seed trays in and out of the house on warm days. Needless to say I am much happier with our cold frame!

Note that you don’t have to use straw for your cold frame! People also use lumber, bricks, and many other materials to create cold frames. Use what’s easily available and/or within your budget!

Easy to assemble, easy to disassemble

In our case we don’t have a permanent spot to keep our cold frame in, so it has moved around the past 3 years. Sometimes it is in our driveway, sometimes next to our shed, and sometimes it is out in the garden.

That means our building materials and cold frame needed to be:

  • easy to carry, and
  • easy to take apart and put back together again.

When the summer plants are dormant we could even put a temporary cold frame on top of one of our late-emerging beds.

Plants stay toasty warm inside, but so do the critters! Watch out for slugs and other plant-munchers.

Recommended placement of your cold frame

You can put a straw bale (or any cold frame) just about anywhere in the yard. However, the best places get south-facing sunlight for early morning sun.

The least effective placement is on the north side of a house, building, or tall tree (not enough sun).

Seed trays and potted plants aren’t the only use for a cold frame. You can put them directly over a half-hardy plant in the garden like these golden snow peas and remove the structure when the weather warms in the spring.

Ideal plants for cold frames

Since the plants inside will only be a little bit warmer than the outside air, cold frames are mostly used for frost-tolerant crops during the winter. Check out our article Easiest plants to grow in the fall and winter, for a complete list of frost-hardy plants.

Spring transplants under cold frames

You can also use your cold frame to grow out your spring transplants. If you do, you’ll want to pay careful attention to the weather and bring the more tender seedlings inside on nights when it drops below freezing.

Don’t forget that all sugar, snow, and shelling pea varieties have edible greens. Plant Austrian winter peas or any other type and harvest salad greens all winter long.

Too cold – Although most winter crops are at least a little bit frost tolerant, they don’t grow when it is under 40 F outside. They’ll appreciate the cover of your cold frame staying on any time the weather is below 50 F.

Too hot – Likewise, cool weather crops don’t like it hot. If the thermostat says 50 F or warmer, crack the cover or take it off completely.

You’ll start to get a feel for how warm or cool your cold frame stays as time goes on!

These tomato seedlings were grown out in our straw bale cold frame.

As the weather warms…

By spring, you’ll start leaving the cover off of your cold frame all the time. We usually leave our cold frame up until we’re well past any freak late freezes.

Then we give the straw bales a second life by spreading them under our rows of blackberry and raspberry brambles. When the berries leaf out and send out new canes they rest on top of the bales and block light from competing weeds. While the bales are under the brambles, they become hosts to mushrooms and other soil organisms.

We think the summer mushroom colonies mycoremediate any herbicides the previous farmer used. Ideally, you can find straw bales that don’t have pesticide residue so this issue doesn’t have to be a concern.

By fall the bale weed barrier has rotted enough to lose its form. The bales get a third life in the garden when they’re dumped in the chicken run to be dismantled as a precious feast by our laying hens. At that point they become compost that we can use to fertilize our next batch of seedlings!

One of our chickens enjoying what’s left of a straw bale.

We hope this article helps you better understand what cold frames are, how to use them, and how to build one yourself.

Happy gardening!

-Eliza @ GrowJourney
Master Gardener, Master Naturalist, Permaculture Instructor

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How to Build Cold Frames

Used to protect tender plants or rooted cuttings during the colder months, a cold frame is simply a box with a transparent lid or cover. It acts as a passive solar energy collector and reservoir.

During the day, the sun’s rays heat the air and soil in the frame; at night, the heat absorbed by the soil radiates out, keeping the plants warm.

A cold frame is useful at other times of year as well. In spring, it provides an ideal environment for hardening off annual flower and vegetable seedlings started indoors. Seeds of many plants can be sown directly in the frame and grown there until it’s time to transplant them to the garden. In summer, you can replace the cover with shade cloth or lath, creating a nursery for cuttings.

Set up your cold frame in a site protected from harsh winds by trees, shrubs, a fence, or a wall. To ensure that the frame will receive as much sunlight as possible, orient it to face south or southwest.

Sinking the frame 8 to 10 inches into the ground increases heat retention significantly. Make sure the location has good drainage, since you don’t want water to collect around the frame after every rain.

Building a Cold Frame

1. Start by selecting a cover, since its size will often determine the dimensions of the frame. Good choices include an old window sash or storm window; if you don’t have one on hand, look for recycled windows at garage sales. You can also make a cover out of clear acrylic or fiberglass sheets sandwiched between narrow strips of wood and reinforced at the corners with metal corner plates. Polyethylene film stapled to a wooden frame is another option; it’s quick and inexpensive, though it lasts only a year or so. Make sure the cover isn’t too heavy to lift easily. Don’t make it too wide, either, or you’ll have a hard time reaching the plants inside the frame; a width of 2-1/2 to 3 feet is ideal. A length of at least 4 feet will allow you to grow a variety of plants.

Build the frame from lumber, such as rot-resistant redwood or cedar or less expensive plywood or scrap lumber. The frame should slope from about 1-1/2 feet high at the back to a foot high at the front; this traps the most heat and lets rainwater run off. For strength, reinforce the corners of the box with vertical posts. Attach the cover with galvanized steel hinges and apply weather stripping around the top edges of the box.

2. Ventilation is vital to prevent overheating. A minimum-maximum thermometer is useful for keeping track of temperature fluctuations. Plan to prop open the cover when the temperature inside reaches 70 degrees to 75 degrees F/21 degrees to 24 degrees C. Close the cover in late afternoon to trap heat. (If you won’t be around during the day, you can buy a nonelectric vent controller that will automatically open and close the cover at a preset temperature.) On very cold nights, drape the frame with an old blanket or piece of carpet to provide extra insulation.

Cold Frames

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  • 3 Haxnicks Easy Net Grow Tunnels


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  • Modular Cold Frame


  • Deluxe Cold Frame 122cm long x 91cm wide


  • Deluxe Cold Frame 122cm long x 61cm wide

  • Extension Kit For Modular Cold Frame

  • 5 Haxnicks Easy Net Grow Tunnels

  • Deluxe Cold Frame 91cm long x 61cm wide

  • Two Tier Bench for Modular Cold Frame

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  • 3 x Haxnicks Easy Poly Tunnel: Ready Assembled

  • 2 Haxnicks Giant Easy Net Tunnel

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  • Haxnicks Giant Poly Easy Tunnel

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Whether you live in cozy space, you’re new to growing or you just don’t need much room for your plants, a small greenhouse is a great way to keep your plants safe and warm all year long without having to invest in a large structure for your garden.

They come in all shapes and sizes. They range from truly mini greenhouses for tiny succulents and seedlings to compact greenhouses that pack a lot of room for growing into a relatively small area by depending on efficient use of space.

8 Best Small Greenhouses

  • Best Overall: Home-Complete Mini Greenhouse
  • A Close Second: Educational Insights Classroom Greenhouse
  • Another Favorite: Flower House Pop-Up Plant House
  • Best Mid-range Option: 4 Tier Mini Greenhouse
  • For Those on a Budget: Mini Pop Up Greenhouse
  • Most Spacious Greenhouse: Quictent Updated Mini Greenhouse
  • Tiniest Greenhouse: Zenport Balcony Greenhouse
  • Best Hard-Cover Greenhouse: Ikea White Indoor/Outdoor Greenhouse

Best Overall: Home-Complete Mini Greenhouse

  • Space: 2,052 square inches of space to place plants
  • Type: Tall, four-tiered greenhouse
  • The High Points: on wheels, good cover, lots of space
  • The Not-So: heavy

Our favorite small greenhouse is the Home-Complete Mini Greenhouse. It is a four-tiered, tall and thin greenhouse on wheels.

The Home-Complete Mini Greenhouse is well-constructed and easy-to-use. That makes it the ideal small greenhouse.

Compared to other small indoor/outdoor greenhouses, it has a large amount of space for setting up plants and stands alone. So all you need to get started is the greenhouse. That is the case regardless of what the ground beneath it looks like.

Since the greenhouse is on wheels, it is easy to move it to where you need it to be.

What Reviewers Say

Reviewers are overall happy with the greenhouse. They say that the outside cover is thick, durable and fits exactly how they hoped it would.

The cover also insulates the greenhouse well, and in direct sunlight may even overheat. So it is key to keep an eye on it and ventilate it on sunny days.

They also warn that if not properly installed, the shelves are liable to move about. The kit includes zip-ties in order to lock them into place when you don’t want to move them. They are essential for keeping the greenhouse together.

Features & Considerations

The Home-Complete Mini Greenhouse is a little over five feet in height. It stands 63 inches tall, and is 27 in. x 19 in. at its base.

Between the four shelves, there are 2,052 square inches of flat space for putting plants. That makes it one of our most spacious small greenhouses.

The greenhouse weighs 12 pounds. It is one of our heaviest greenhouses. However, it is also one of the most mobile because of the wheels.

Each shelf is rated to be able to hold up to 24 pounds. That adds up to a total of 196 pounds for the entire structure.

The highest shelf has more vertical space for plants. That is due to the triangle shape of the top of the green house.

So the largest plants should be placed there if all four shelves will be utilized. Each of the shelves is removable. So it is also possible to adjust the number of shelves to the height that is necessary for your plants.

The greenhouse comes with a PVC clear cover, which is thick and heavy-duty. It is waterproof and also traps heat to keep the plants warm during cooler weather.

The inside of the greenhouse can be accessed via a weighted flap. You can roll it up to leave the greenhouse open.

A Close Second: Educational Insights Classroom Greenhouse

  • Space: 1,368 square inches of space to place plants
  • Type: Medium, two-tiered greenhouse
  • The High Points: quality cover, snug fit, sturdy
  • The Not-So: heavy, weak points at zippers

Although the Education Insights Classroom Greenhouse is marketed for educational and classroom use, it also makes an excellent small greenhouse for anyone, not just teachers and students.

Its thoughtful design is valuable for any gardener and its strong build holds up not just to children in a classroom, but pets, outside pests and weather events, too.

The plastic cover makes it easy to see your plants, even while they’re safely inside the greenhouse. It is also more attractive than some other covers on the market, too.

The clear plastic does not get dirty easily, so this small greenhouse also works well for displaying plants.

Reviewers were generally happy with the Educational Insights Classroom Greenhouse, saying that it fit their need for a small, sturdy greenhouse. Most used it inside, but some also used it outside, and said that it stood up to medium winds and normal rainfall well.

One thing that reviewers particularly liked about the Educational Insights Classroom Greenhouse is that the cover fits snugly over the metal framing. That makes it more strongly protected and easier to move than if the cover were loose.

The problem with the snug fit, some reviewers point out, is that you must be gentle when opening and closing the zippers to access the plants. You’ll need to do that in order to not break them with the vinyl cover pulled tight.

The greenhouse measures 19 in. x 36 in. at its base and is 38 inches tall at its highest point. It has 1,368 square inches of growing area between its two shelves and the top shelf allows you to place taller plants inside. The entire greenhouse weighs 8 pounds.

Another feature that is very useful is that the shelves can be easily removed to adjust to your planting needs. If you plan to put a heavier plant inside the greenhouse, you can remove the bottom shelf and place the plant directly onto the surface where the greenhouse is as to not stress the shelf.

If you need more vertical space than one shelf allows for, then you can remove the top shelf and place the plant inside, with double the space.

Another Favorite: Flower House Pop-Up Plant House

  • Space: 576 square inches of space to place plants
  • Type: Pop-up greenhouse
  • The High Points: pops up on its own, portable, no weight limit
  • The Not-So: small amount of space for plants

Flower House is the master of Pop-Up greenhouses of all sizes, which makes setup and take down of your greenhouse a breeze. It’s also highly portable, because it folds up into a circular carrying case.

This small greenhouse is ideal for people who don’t want to go through the hassle of setting up with metal poles and shelves and is a great choice for gardeners who want to shift the green house around.

Since it’s very light and is just placed onto any hard surface (a table, the ground, sidewalk, etc), it’s also very flexible.

Reviewers rave about the fabric that the outside of the flower house is made of. The outside plastic is super durable and much thicker than similar “pop-up” models. Best of all, it is heat-resistant, so it is not liable to melt due to internal heating or degrade due to external sources.

They also love how well the greenhouse traps heat, but advise that it is suited for mild winters, but might need additional fortification if there will be extreme weather like snow.

Some reviewers also noted that since the method of holding the greenhouse in place is with stakes, it is not ideal to install over a hard surface if not weighed down by another method.

The Flower House Pop-Up Greenhouse is similar to a cube in shape, measuring 24 in. x 24 in. x 20 in. The area for growing is approximately 575 square inches, which is one of the smallest on our list, so it may not be the best choice for someone looking to have many plants.

Compared to other greenhouses, it is more vulnerable to the elements because it is not weighed down by metal poles. In total this greenhouse weighs 6 pounds.

It also does not have a built-in way of securing it, so in order to make it fit for outside use in less-than-perfect weather, the provided stakes will have to be installed and it is advisable to place the greenhouse near a structure to help block the wind.

The outside material is made of a woven plastic, making it stronger than a simple plastic cover. It is less susceptible to damage due to physical blows because the entire plastic cover is in one piece.

In order to access the plants, there is a zippered flap which can be tied up to allow airflow and easier access.

Best Mid-range Option: 4 Tier Mini Greenhouse

  • Space: 1,836 square inches of space to place plants
  • Type: Tall, four-tiered greenhouse
  • The High Points: lots of space, good value, includes two covers
  • The Not-So: heavy, doesn’t support a lot of weight, not very durable

For a greenhouse with an excellent price vs. space ratio, the 4 Tier Mini Greenhouse is our go-to option. Its multilevel design makes efficient use of its size to minimize the amount of room that the greenhouse takes up while maximizing the space for plants all at a low cost.

The bottom three levels of the greenhouse are smaller than the top one, allowing for variation in which plants can be placed on which shelf, and each shelf is able to support 6-11 pounds. Although this isn’t as much weight as some other options, for a few small plants, it is enough.

Overall, reviewers were pleased with the greenhouse’s capacity to maintain heat inside and generally protect plants from the elements, especially wind, although some cautioned that it should be secured if it will be in high winds to eliminate the possibility of it being blown over.

The downside to being so well protected if that some reviewers found that it overheated inside and there is no option for ventilation without the greenhouse being fully opened.

Reviewers also warned that the shelves should not be overloaded. The thin material that the shelves are made out of is excellent for maximizing the amount of space for plants to grow upward, but it does limit how much weight each one can take.

The vast majority of reviewers were happy with the greenhouse, even if they admitted that it is not the sturdiest one. They also agreed that it has a good price to quality ratio.

Features & Consideration

All in all, including the shelves of all four levels, this small greenhouse has 1,836 square inches of planting space. The entire greenhouse is 27 inches by 19 inches at the base and stands at 63 inches tall at its highest point. It’s similar in size to an adult standing upright.

Another thing that we love about this small greenhouse is that it includes two covers, one standard PE cloth cover and one non-woven fabric cloth, which can be used for shade.

Both of the covers have a similar shape, drape over the metal frame and the opening is a long, zippered flap, which can be rolled and tied up when accessing the plants.

Its frame is made of high-quality tubular steel with powder coating and each shelf is constructed of a heavy-duty bearing net. The greenhouse weighs 10.6 pounds.

Because of its height and weight, it can be a little bit difficult to move, especially because it does not have any wheels or other mechanism to move it, so it is best to choose a place for it and leave it there if possible.

For Those on a Budget: Mini Pop Up Greenhouse

  • Space: 729 square inches of space to place plants
  • Type: Pop-up greenhouse
  • The High Points: well insulated, easily foldable, pops up when opened, comes with storage bag
  • The Not-So: cannot be placed on flat surface if there is wind

The highly foldable, easily stored Mini Pop Up Greenhouse is the small greenhouse answer for those on a budget. It’s convenient with its simple carrying case, folding design and small stakes, and just about sets itself up completely once it’s out of the bag, since it springs open.

All of those positives come at the most accessible price on our list. Although the greenhouse is small, it still has enough space for a few plants and is ideal for one or two large plants in pots, with significant height capacity. It also could work with several smaller plants.

Reviewers that use this small greenhouse in their garden or inside their house love it. In the garden, you can stake it down and it does an excellent job of holding heat, while in the house, the foldable design makes it easy to move.

What some reviewers had trouble with was putting it over a hard surface, where they could not stake it down, and therefore where it was affected by winds, the light plastic occasionally blew it over.

Reviewers have mixed feelings about the outside plastic. Some say that they found it to be super durable and did an excellent job of holding in organic heat, while others worried that the plastic might not hold up to heating with an internal heat source.

The body of the greenhouse consists of clear PVC. A simple fabric holds it together at the seams.

Along the bottom, it has flaps that spill onto the ground. You can stake those down to seal in the heat and make the greenhouse more wind-resistant.

It measures 27 in. x 27 in. at the base and at its tallest point is 31 in. tall. The total growing space is 729 square inches, and there is no structural limit to the weight of what can be put inside, since it is placed directly onto the surface where the plants are sitting. The entire greenhouse weighs a little less than 2 pounds.

You can access the inside of the greenhouse via a zip flap, further insulating the space. When open, you can tie it up using two small strings near the top of the flap.

Most Spacious Greenhouse: Quictent Updated Mini Greenhouse

  • Space: 2,556 square inches of space to place plants
  • Type: Long, rectangular greenhouse
  • The High Points: lots of space for plants, allows for tall plants
  • The Not-So: plastic cover not durable

If you have many plants or if you have tall plants that just will not fit into the smallest greenhouses, then a greenhouse like the Quictent Updated Mini Greenhouse might just be the option for you.

It combines the compact design that makes small greenhouses practical, but there is still enough space to store many large plants.

It can be placed directly onto the ground or on top of another surface and it is even large enough for you to add your own shelves inside if you need them.

One of the best things is that, without a built-in base or shelves, you are not limited to the weight that the base of shelves can hold, which is key in a greenhouse with the capacity to hold many large plants.

Reviewers love how durable and strong this greenhouse is. They recount how it withstood high winds and sub-zero temperatures and that even in those conditions, the temperature within the greenhouse remained reasonable, as long as it was fortified with blankets.

They also point out that you can use it for other purposes, such as protecting an outdoor pond, since the bottom is open. The one warning that they give in relation to the bottom is that it is essential to find a surface that will also maintain the heat and hold up to the weight of the plants.

In general, reviewers agreed that this greenhouse does better in cooler temperatures than in hot ones. Some users had trouble with the plastic deteriorating over time after being in the sun for extended periods of time to the tune of months.

This greenhouse measures 71 in. x 36 in. in length and width and at its highest point, it is 36 inches tall. It is supported by a heavy-duty powder coated steel framework which are connected by plastic PVC corner pieces. All together the greenhouse weighs 9 pounds.

The outside cover has a green tint and consists of a PE semi-transparent cover. It has two access points to the inside, both of which are on the same side, and you open them using a zipper. When open, there are small strings to tie them to the arch of the greenhouse to make working inside of it easier.

When you buy the greenhouse, Quictent also includes 50 white t-type tags for marking plants within the greenhouse. The total area where you can place plants inside the greenhouse is 2,556 square inches.

Tiniest Greenhouse: Zenport Balcony Greenhouse

  • Space: 160 square inches of space to place plants
  • Type: Short, single-tiered greenhouse
  • The High Points: space-efficient, easy to assemble and break-down to store
  • The Not-So: too small for some needs

If limited space is your most important constraint, the Zenport Balcony Greenhouse is the small greenhouse for you. “Small” might even be an understatement for this greenhouse – it really falls into the category of “mini.” Put completely together, it still will fit into most people’s laps.

Given its compact size, it is an ideal greenhouse for indoor or outdoor use. Inside, it can fit onto small surfaces in a small house or apartment, while outside, it is ideal for balconies as is in its name.

Small plants like seedlings, herbs and succulents go well in this greenhouse. It is worth choosing a short plant that grows slowly or you may find yourself needing to upgrade quickly, especially because the sides of the greenhouse are shorter than the center section.

Since the greenhouse is so simple, just a small metal frame with a thick, plastic transparent cover, setting up this greenhouse is a breeze, according to reviewers. It is also easily foldable to be stored quickly and compactly.

The access to the plants is through a zipper which appears to be on the front (the longer side) of the greenhouse, but some reviewers mentioned that their greenhouse actually opens on the side. Because of the greenhouse’s small size, the entire thing is easily accessible through the zipper, no matter which side it is on.

The greenhouse’s overall size is 17 in. x 10 in. at the base and the tallest part measures 12 in. The shelf where you can place plants measures approximately 160 square inches. The small greenhouse only weighs 2 pounds by itself.

It consists of a powder-coated green finish steel frame shaped in an arc with a thick, waterproof plastic cover to insulate the plants. On the bottom there is a removable grated shelf to place the plants on.

Setup is easy; all you need to do is to unfold the frame, place the shelf into it and cover with the plastic cover. The cover has zip ties to hold it in place and you can access the contents of the greenhouse via a zipper on the shorter side.

Best Hard-Cover Greenhouse: Ikea White Indoor/Outdoor Greenhouse

  • Space: 136 square inches of space to place plants
  • Type: Tall, hard cover greenhouse
  • The High Points: cute, protects contents from physical blows well
  • The Not-So: fragile top – must pick up from bottom, not well sealed

This hard-cover greenhouse from Ikea is an excellent choice for greenhouses in a place where plants have to contend with animals to survive, whether it’s the house cat or the backyard squirrels. The casing is fragile for lifting, but when it comes to batting paws, it holds up well.

It also is one of the most aesthetically pleasing greenhouses on our list, with the true Ikea style in the white frames and clear plastic siding. It can work as well as a greenhouse as it can for decorative purposes.

Reviewers often chose this small greenhouse for its cute, but hard exterior. They noted that it allowed them to display their plants with its clear walls. It also protects them from the elements and their pets.

According to some users, the white frames are particularly nice. That is because they do not distract at all from the contents of the greenhouse. Instead, they complement it.

They warn that it should be handled with care. That is because of some weaknesses in the top part of the greenhouse. However, that as long as they were careful when lifting, they did not have any other troubles with its structure.

Some reviewers warn that it might not be the most well-sealed greenhouse, especially near the doors. That is because in some cases, there was a small gap between the closed doors and the top of the greenhouse.

To solve this, you could apply caulk to the greenhouse. However, as is, it is far from sealed off, although reviewers recognized that it probably could still retain a significant amount of moisture.

The thick walls of the greenhouse limits the total area where you can place plants. The flat inside area is approximately 136 square inches.

That is a wonderful place for seedlings or small succulents. However, it may not be ideal for larger plants.

Overall, the size of the greenhouse is 13 in. x 8 in. at the base. It is 18 in. tall at the tallest point – where the top panels meet.

You can adjust them for style and space. So some taller plants that don’t necessarily need to be enclosed may also fit.

Another thing to keep in mind is that the greenhouse is relatively heavy for its size because it is made of plastic instead of netting and softer materials. Overall it weighs 7.6 pounds and you must lift it from the bottom because the connection from the base to the side panels is weak.

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The Complete Small Greenhouses Buyer’s Guide

  • What Makes a Good Small Greenhouse?
  • Selection Criteria: How We Ranked the Best Small Greenhouses
  • Frequently Asked Questions (FAQs)

What Makes a Good Small Greenhouse?

  • How Much Space You Have
  • How Much Space You Need
  • How Protected Your Plants Need to Be

The answer is: it depends on what you plan to use it for. We know that’s not very satisfying and it can be hard to know what is best for you, but there are a few things to consider that can help narrow down what features you should look out for and prioritize.

How Much Space You Have

Since you’re looking for a small greenhouse, we imagine that you might not have much space. It’s good to think about space in all three dimensions, length, width and height, to determine what greenhouse might be best for you.

For example, if you don’t have much ground space, but you have six or seven feet vertically, a tiered greenhouse might be the best for you. If you don’t have much outdoor green space, but a lot of concrete space, a greenhouse that plays to that might also be appropriate.

How Much Space You Need

The other question to consider is the amount of space that you need to grow. If the greenhouse is for one or two plants, then you don’t need the same space as that required for hundreds of seedlings.

It is also important to consider what kind of space your plant needs; a tree needs a different shaped space than a flower, and the greenhouse you choose should reflect that.

How Protected Your Plants Need to Be

Different materials have different properties, so considering the needs of your plants can help you decide what you need the cover for your greenhouse to be made of. Some are more resistant to weather, while others hold in heat better. The covers on our list are made of the following materials.

  • Transparent or Colored PVC Cover
  • Transparent or Colored PC Cover
  • Vinyl Cover

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Selection Criteria: How We Ranked the Best Small Greenhouses

  • Dimensions and Weight
  • Planting Space
  • Installation Method and Type

When choosing which small greenhouses are the best out there, we took a number of factors into consideration. We know that no one thing makes a greenhouse perfect for everyone, but there are a few things that we value for every greenhouse, such as:

  • Material Quality
  • Efficient Use of Space
  • Sturdiness
  • Resistance to Weather Phenomena

All of the greenhouses on our list embody these qualities to some extent. We also considered a few other factors that varied greatly based on each greenhouse, which we’d like to highlight.

Dimensions and Weight

Product Dimensions – LWH Weight
Home-Complete Mini Greenhouse 27 in. x 19 in. x 63 in. 12.5 lbs.
Educational Insights Classroom Greenhouse 19 in. x 36 in. x 38 in. 8 lbs.
Flower House Pop-Up Plant House 24 in. x 24 in. x 20 in. 6 lbs.
4 Tier Mini Greenhouse 27 in. x 19 in. x 63 in. 10.2 lbs.
Mini Pop up Greenhouse 27 in. x 27 in. x 31 in. 2 lbs.
Quictent Updated Mini Greenhouse 71 in. x 36 in. x 36 in. 9 lbs.
Zenport Balcony Greenhouse 17 in. x 10 in. x 12 in. 2 lbs.
Ikea White Indoor/Outdoor Greenhouse 13 in. x 8 in. x 18 in. 7 lbs.

Each greenhouse has its own shape and size, which means that there is likely one greenhouse that fits your size needs. Some are tall and thin, while others are longer and flatter, and some are just outright compact. Weight varies from 2 pounds to 12 pounds.

We generally favored greenhouses on the larger spectrum of small greenhouses, but we also included a few that are very tiny. Weight depends largely on material, so it doesn’t necessarily correspond with size, but more heavy-duty materials tended to be heavier so we favor heavier greenhouses.

Planting Space

Planting space refers to the area of flat surfaces where you can place plants. Some of these areas vary depending on whether you remove a shelf or where you place the greenhouse, but we often prefer greenhouses with more planting space so you can maximize how many plants you can put into your greenhouse.

Installation Method and Type

Product Installation Method Type of Greenhouse
Home-Complete Mini Greenhouse Poles plus cover Four-Tiered
Educational Insights Classroom Greenhouse Poles plus cover Two-Tiered
Flower House Pop-Up Plant House Pop-Up Direct to ground
4 Tier Mini Greenhouse Poles plus cover Four-Tiered
Mini Pop up Greenhouse Pop-Up Direct to ground
Quictent Updated Mini Greenhouse Poles plus cover Direct to ground
Zenport Balcony Greenhouse Poles plus cover Single-Tiered
Ikea White Indoor/Outdoor Greenhouse Some tools required Hard cover

Most of the greenhouses fall into a few different categories based on the type of greenhouse and how you set it up. The more complex greenhouses to set up do require assembly, but a few simply just open up on their own.

Different types and assembly methods have their pros and cons, but we preferred ones that are relatively simply and require few tools, if any at all.

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Frequently Asked Questions (FAQ)

  • Can I use my greenhouse both inside and outside?
  • Is there a weight limit for the plants that I put in the greenhouse?
  • Are the greenhouses heated?
  • How do I set up the greenhouse?
  • Are there limitations to having a small greenhouse, and if so, how do these greenhouses address them?

Can I use my greenhouse both inside and outside?

Yes, all of the greenhouses on our list are fit for both indoor and outdoor use. There are a few things to keep in mind, though, if you choose to place your greenhouse outside.

The first is that not all covers are the same, and as such it is necessary to consider in what conditions you will be using it in. Some are more liable to break in inclement weather situations, such as under heavy rain or wind.

In others, the plastic may not be the sturdiest, and there is a possibility that it could melt or deteriorate under very strong sun.

Another thing to keep in mind is how you install the greenhouse to the ground. You stake some into the ground, while others simply sit on top of it.

Those with stakes work well outdoors, while others might be more vulnerable if there is no way to hold it firmly down.

Is there a weight limit for the plants that I put in the greenhouse?

With some of the greenhouses, there is a weight limit. The greenhouses that have shelves generally are not able to support as much as the other ones, ranging from 6 pounds to 25 pounds, depending on the design and make of the shelf.

Some greenhouses install directly onto the ground that they sit on. In those cases, the weight limit is not that of the greenhouse, but the surface that you’ve installed it on limits it.

Are the greenhouses heated?

None of the greenhouses on this list come with a heating mechanism installed. Some have special covers that have a design for trapping heat inside and thus have a natural heating system.

Others recommend certain heaters to use with them, such as ceramic heaters or seedling heaters, which work best with the shape of the greenhouse or the materials that the greenhouse is made of.

It is best to use caution when heating the greenhouse with a heater. There are other measures such as wrapping it in a thick blanket that you can take before resorting to a heater.

Before using it, it is best to check on the kind of plastic the greenhouse uses to see if it is suitable to use with a heater.

How do I set up the greenhouse?

There are a few different setup methods for these small greenhouses which vary from very little work to a lot of work; however, all of the greenhouses come with all of the necessary pieces you need to set up.

The first and easiest set-up method is the pop-up greenhouse. These greenhouses tend to install directly onto the ground and when you take them out of their package, you simply need to unfold them, and they set themselves up.

In order to secure them, most come with small stakes that you should drive into the ground near the corners of the greenhouse.

Another setup method is with poles, elbows and a removable cover. Although this setup takes a little bit more work, it is more flexible to your desires. It is most common with greenhouses with shelves and just involves putting the pieces together according to instructions.

The final method is more complicated and is only in the case of the hard cover greenhouse. It requires some basic tools to screw the pieces of the hard plastic together.

Are there limitations to having a small greenhouse, and if so, how do these greenhouses address them?

Having a small greenhouse means that you will not be able to step inside of it to care for your plants. Unlike traditional greenhouses, small greenhouses are meant to just house the plants and in order to manipulate and water them, you need to work from the outside.

The good news is that all of the small greenhouses on our list are designed with this in mind. They often have large zippered flaps which can be secured for easy access and are much easier to ventilate than a traditional large greenhouse.

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Greenhouse Buying Guide: The 10 Best Greenhouses

Greenhouses are an excellent way to help extend your growing season, protecting plants from extreme temperatures and the elements, as well as for starting plants from seeds. They are generally quite reasonably priced and are made from durable materials that should give you several years of use.

While there are many benefits to greenhouses, it’s important to remember watering will be an issue, as the natural rains will not reach your plants, and overheating can be an issue in extreme summer heat.

There are three main types of greenhouses:

  • Cold frame, which are bottomless and can easily be moved. They are ideal for the early spring and late fall seasons to help protect and encourage plants to grow that would otherwise perish due to cooler temperatures.
  • Starter, which are small to medium in size and ideal for starting seedlings and hardening off plants which will be transplanted to your gardens.
  • Grower, which are the largest and can be used to start seedlings, harden off plants, grow crops to harvest, and even cure them for storage.

No matter which type you purchase you’ll want to consider if there is adequate size, ventilation, insulation, and durability for your needs. All of these variables will ultimately impact the final price of your unit.

With the above information in mind, in no particular order here are 10 of the greenhouses we consider to be best, based on available features and average customer ratings and reviews.

You don’t need a grand greenhouse to garden year round. A cold frame–which is essentially a warming hut for seeds and seedlings–can fend off frost to extend your growing season through the iciest months. Easy, economical, and space efficient, a cold frame deserves space in a sunny spot of every garden:

Above: A cold frame in fashion designer Courtney Klein’s garden in San Francisco’s Mission District is built of 10-foot-long redwood planks. For more of her garden, see Garden Visit: Courtney Klein’s Mission District Backyard. Photograph by Jamie Beck.

A cold frame is nothing more than a box with a clear lid that to trap heat and shelter plants from low temperatures and battering weather. Typically bottomless for good drainage, cold frames sit low to the ground and have no artificial heat source. A transparent lid absorbs sunlight and can be lifted for air circulation (or kept shut to keep out the elements).

Above: Historically, cold frames were built as greenhouse extensions tucked against the outer walls with southern exposure as seen (with their glass lids removed) outside Victorian glass houses. They offered a place to harden off seedlings on their journey from the cozy confines of the greenhouse to outdoor planting beds. Photograph courtesy of Annie Guilfoyle, from Before & After: A Kitchen Garden in Sussex, England.

What are the the benefits of cold frames?

Cold frames…

  • Prolong the growing season so you can harvest greens and cool-season vegetables in winter. Cold frames create a microclimate that can be a zone and a half warmer than your garden.
  • Protect plants from wind and rains during stormy months.
  • Provide a frost-free haven for tender plants that won’t survive freezing conditions. Move plants into a cold frame and insulate them well to lull them into dormancy until the weather is warm enough to transplant them into the garden.
  • Have ideal conditions to gradually acclimate seedlings grown indoors to conditions outside without having to carry them in at night.
  • Offer a good place to sow seeds in the spring (and enable you to start earlier in the season).
  • Are versatile; remove the lid and a cold frame becomes a raised garden bed in the warm months.
  • Are easy and affordable to make (or purchase).

Above: For 10 to buy, see 10 Easy Pieces: Cold Frames.

Where is the best place to put a cold frame?

To maximize warmth, light exposure, and weather protection for plants, cold frames should be sited in a south-facing position. Other site considerations are drainage and protection from wind. Placing a cold frame on a forward-facing slope facilitates drainage (as does digging down and adding a layer of gravel under a layer of top soil beneath a flat cold frame base). While not required, it is recommended that the back of the frame be higher than the front to capture the most sunlight and allow snow and water to drain off the top.

Take a cue from history and put your cold frame adjacent to another outbuilding for added insulation and to buffer it from weather on one side.

Can I make my own cold frame?

Yes. Cold frames are easy and affordable to make, requiring little more than a few boards, an old window (or piece of glass or plastic), some hinges, screws, and a bit of muscle. This Old House offers a How to Build a Cold Frame tutorial using a salvaged window, and Martha Stewart has her own meticulous step-by-step instructions.

Not ready to commit to a permanent cold frame structure? Lay an old window (or a sheet of plastic or glass) over a high-sided raised bed to construct a temporary cold frame.

Above: If you like the idea of a cold frame, but are DIY-averse, there are many pre-made cold frame options. See our roundup 10 Easy Pieces: Cold Frames. Photograph via Farmer D. Organics.

What vegetables grow best in winter cold frames?

Low growing, cool-season plants are the best inhabitants for winter cold frames. Vegetables that can tolerate lower temperatures include carrots, radishes, and leeks, as well as winter lettuces, spinach, and chard.

Where to put a cold frame

It depends on the purpose of the cold frame. It can be used to warm soil in spring, allowing seeds such as carrot to germinate earlier, giving an earlier harvest. It can also be used as a mini green house to raise seeds in trays and modules. And it can be used to shelter semi hardy plants from frost. Lastly it can be used to wean plants raised in warmth before putting them out i.e. harden them off. Why not start out in a sunny area, warming a bed, then move it about as need be? I have carrot and spring onion germinating in soil under mine, whereas carrot in beds are still not up. And I raised seed in modules too. In june mine will shelter chillis. The extra shelter makes a big difference. At the moment I can keep the panels closed during the day without issues, but in summer of course they must be opened.

You didn’t say what it is made from. If it is light, then take care. One of mine flew 20m across the garden. You must make sure it is pegged down if light e.g. al and plastic. Glass ones are okay obviously. Incidentally one of mine came from Lidl, it is very very good value for money, better than ones costing twice as much in local,garden centres. My Halls one is fabulous.

How to Build a Cold Frame for Your Garden

By Charlie Nardozzi, The Editors of the National Gardening Association

A cold frame is, essentially, a mini-greenhouse. By growing plants in a cold frame, you can harvest cold-tolerant vegetables year-round, even if you live in zone 5 where winter temperatures can dip as low as –20 degrees F. Cold frames are also great for hardening off seedlings, growing cold-tolerant flowering annuals like pansies, and rooting cuttings from your garden.

Build a cold frame to extend your growing season.

A cold frame usually consists of a wooden box covered with windowpanes or clear plastic. The frame rests directly over the soil in your yard. You can purchase a premade cold frame for $100 to $200, or you can create your own simple cold frame by following these steps:

  1. Build a 3-foot-x-6-foot box from untreated lumber. Cut the box so that the back is 18 inches high, sloping to a front height of 14 inches.

    This sloping angle enables more sun to reach the plants, and it sheds rain and snow as well.

  2. Hinge an old window sash over the top of the cold frame.

    If the window sash has no glass, use fiberglass or polyethylene to create a sealed growing environment You can insulate the cold frame by adding rigid foam insulation around the insides of the cold frame and by weather stripping along the top edge. In extreme cold, cover it with heavy burlap or an old blanket. Remember to uncover the coldframe when the sun comes out so the plants can warm up again.

  3. Position the cold frame so that it faces south.

    If the south side isn’t practical, then use the west, east, or north side in that order of preference. It’s best to put a cold frame next to a structure, such as a house, to protect it from cold winds.

Even though the purpose of a cold frame is to trap heat, on sunny days, even in winter, a cold frame can get so hot that it burns the plants. Check your cold frame once a day on sunny days, opening or venting the top slightly to allow hot air to escape. You can even provide some shade by putting a piece of shade cloth over the glass.

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