- How to choose the right potting compost for your plants
- Note on the word ‘compost’
- Seed compost
- Multi-purpose compost
- Potting compost
- John Innes
- Which Potting Compost Is Best For Indoor Plants?
- When I apply worm compost & compost:
- How I apply the compost:
- Common questions regarding compost for houseplants:
- Where to buy worm compost and regular compost:
- Houseplant Pruning Guide: How To Prune Indoor Plants
- When to Prune Houseplants
- How to Prune Indoor Plants
- Plants NOT to be Pruned
- Winter is a great time to groom and prune houseplants
- Healthy Houseplants
- How to Prune Houseplants
- Houseplant Pruning Tools
- Pinching Back Houseplants
- Houseplants to Prune/Pinch Back
- How to Water Your Indoor Plants The Right Way
How to choose the right potting compost for your plants
In the olden days, gardeners had to create their own potting compost types and it could be incredibly variable. After the Second World War, standardised ‘recipes’ emerged, and today there are dozens of types available in the shops.
But all that choice can be confusing and overwhelming. It’s hard to tell what the differences are and if you are using the right compost.
So here’s a handy guide to potting compost types, mixes and uses.
Note on the word ‘compost’
By compost, I don’t mean the black recycled compost you get out of the compost bin. This is a soil improver and should never be used to fill pots or seed trays. It would be like putting young plants in pure manure mixture, and will definitely kill them.
You need the bags of compost that are designed for pots, which is why it is called potting compost.
And you also don’t want to use topsoil in containers. This is designed for topping up borders and filling raised beds. Ordinary garden soil does not have enough nutrients or water retention to be used in pots.
Seed compost is a mixture designed for sowing seeds into. It’s finer and less lumpy than standard potting compost, and is also light and well-drained.
You can also use seed compost to repot seedlings and young plants. But it doesn’t have enough nutrients to support larger plants.
This is also called general purpose compost. It’s a middling mix between seed compost and potting compost, and can be used as a substitute for either.
Multi-purpose compost is the best choice if you’re planting small patio pots, hanging baskets, herbs, leafy salads and flowering bedding plants.
But it has less nutrients than potting compost, so be prepared to start adding fertilisers sooner if you’re planting larger varieties. It’s not suitable for established trees and shrubs.
Multi-purpose compost is also available peat-free – please see below for more details on using peat.
This is designed for supporting established plants in pots. There are two main types – soil-based and soilless.
Soil-based composts are designed to mimic loamy garden soil. These are called John Innes.
Many people think John Innes is a brand, but it’s actually a recipe from a gardener by the name of John Innes, and any brand can make it. There are a few different types of John Innes compost with distinct uses.
The JI seed compost is used for sowing seeds. Then there are three JI numbers, each denoting a different recipe. The higher the number, the more nutrients it has and the bigger the plants that can grow in it.
JI No1 is used for potting up small, young plants. When they need repotting in a larger container, you then need JI No2. A year or so later, you should repot the plant into a larger container filled with JI No3 and it won’t need repotting again for a couple of years.
Soil-based composts are good choices for established plants because they are rich in nutrients and retain moisture well. But they are dense and heavy and drainage is not too good, making them the wrong choice for seedlings and containers like hanging baskets.
Be aware that John Innes composts do contain some peat, if you are trying to avoid it.
Which Potting Compost Is Best For Indoor Plants?
Discover what potting mixtures contain and take the guesswork out of choosing the right one to keep your house plants healthy.
At garden centres and nurseries there is often a bewildering array of bags of potting mixtures available to choose from. What do they do for your plants and how do you know which to choose to suit the needs of your plants?
Basically a potting mixture should supply your house plants with all the nutrients and water that their roots would have found if they were growing naturally in the ground. In your home their roots are in confined spaces in containers, so the nutrients and water have to be provided by you in the the potting mixture.
It is very important that the mixture is of the right texture for the plant’s roots to grow strongly; that it holds moisture, yet is free-draining; contains enough nutrients and is changed, or partially changed, at regular intervals. There are two main types of potting mixture. One has a loam or soil base and the other is peat-based.
Never be tempted to use garden soil for house plants. It would need to be sterilized to kill pests and diseases before you could use it. Home sterilizing is messy and expensive. Particular ingredients can be added to ready made mixtures depending on the needs of the plants.
John Innes potting mixtures
These are the best known soil-based mixtures that are commercially available. They consist of 7 parts of loam or soil, 3 parts of peat and 2 parts of coarse sand. The main ingredients are partially sterilized and a slow-release granular fertilizer is added. There are 3 main types, John Innes No. 1, 2 and 3. They each contain different amounts of fertilizer. Look for the John Innes Manufacturers’ Association Seal of Approval when buying.
- Soil-based compost is rich in plant food, and is good for greedy plants which need a regular supply. Some typical uses are as follows:
- It is much heavier than peat-based mixtures and helps to keep large’plants (e.g. strong-growing climbers) and plants with weighty leaves (such as Mother-in-law’s Tongue) from toppling.
- Soil-based compost is also useful for bulbs such as amaryllis, nerines and vallota, and for some of the larger leafy palms which like to be left undisturbed.
- In texture this compost closely resembles the kind of soil in which many cacti and succulents grow in the wild. With peat or grit added to it, it suits these plants very well.
There are a number of ready-mixed soil-based potting mixtures available including those in the John Innes range. All of them provide a rich growing medium for the plant and all release their nutrients to the plant over a long period of time. The nutrients are available for several months. After about 3 months you will need to supply nutrients when you water the plant. The amount you add, of course, depends on the requirements of the plant and the time of the year—whether it is a period of active growth or not.
Holding nutrients and water
The main ingredient of the mixture–the loam or soil—is the bulk which helps to hold the nutrients. The peat in the mixture is spongy and holds water, while the sand keeps the mixture open and airy. It also makes it free-draining.
The disadvantage of a soil-based mixture is that because of the nature of the main ingredient, loam or soil, the quality of the mixture may be variable. It can also be heavy to use and it is possible to overwater plants in a soil-based mixture. Soil-based mixtures are messy and generally not as easy or pleasant to handle as peat-based ones.
- Peat-based compost is light and moisture-retentive, and is ideal for plants which like moist, airy conditions:
- Plants such as African Violets, begonias, Christmas and Claw Cactus, which have fine, hairy roots are at home in this compost. The tender roots run easily through it and pick up water and nutrients.
- Ferns and bromeliads, which are by nature forest plants, thrive in this type of compost, as its texture resembles that of their native woodland compost.
- Peat-based compost is also vital for the healthy growth of tropical or jungle plants, which need plenty of air as well as lots of moisture, as it can be kept constantly damp.
These composts have recently been developed because of the difficulty of obtaining suitable loam at a reasonable price. In this range you can find composts suitable for sowing, potting and general purposes.
The main ingredients are peat and sand with added nutrients. The peat and sand are sterile. They are simply used as the growing medium in which the roots establish themselves. You will have to add all the nutrients the plant needs on a regular basis. The nutrients will be used up quickly by the plant and some will be flushed out of the container and become unavailable to the plant once you start watering.
Many nurserymen and commercial growers favour peat-based mixtures. The plants you buy are likely to have this mixture in their pots.
Hard to moisten
One disadvantage of a peat-based mixture is that it is very light in weight and top-heavy plants may topple over, especially if the mixture dries out. Peat on its own is also difficult to re-moisten once it has dried out. Many ready-mixed brands now include wetting agents to avoid this problem. To re-moisten compost, stand the pot in water to its rim until moisture reaches the top of the compost.
Some plants require the basic soil- or peat-based mixture but need something added to make it just right for their special requirements. There are many additives which can change the character of the mixture.
- Perlite is expanded volcanic rock. It is very light in weight and improves aeration, drainage and water-holding in heavier mixtures. Use with peat to root cuttings.
- Vermiculite is expanded mica. It is light in weight, improves water-holding and holds nutrients well. It is good for lightening heavier mixes and useful in rooting mixtures.
- Grit or coarse sand is added to mixtures to make them more open and free-draining.
- Sphagnum moss is added to mixtures for plants that need open but moist conditions.
- Other materials used to lighten or make soils more open are polystyrene and bark chippings. Rockwool, a coarse fibrous material, holds water well but doesn’t become waterlogged.
Buying and storing composts
These mixtures can be bought weed, pest and disease-free in various quantities from garden centres nurseries, as well as from DIY and supermarket chains. Don’t buy bags that are split – by the time you get them home some nutrients may have been lost. Always buy the freshest compost available.
When I apply worm compost & compost:
I’ve been meaning to do this post for quite a long time now. I mention this topic in many of my houseplant posts and give a brief explanation following it up with “post and video coming soon.” There’s no time like the present so I want to share with you my favorite way to feed my indoor plants. Here’s how I use worm compost and compost for houseplants in my indoor and outdoor gardens.
Here’s my reasoning for nourishing my houseplants with this dynamic duo: this is how these plants get fed when growing in their natural environments. Many houseplants are native to sub-tropical and tropical environments and get their nourishment from plant matter falling from above. Compost is basically decomposed organic matter. And of course, earthworms also inhabit these areas and aerate and enrich the soil.
Why not feed houseplants the same way?
When talking about worm compost, I’m not referring to vermiculture and raising my own earthworms. I buy the worm compost (organic of course) in a bag from a local garden center. My houseplants seem to love it and are healthy and happy. The only houseplants I don’t use it for are my Lucky Bamboo and Lotus Bamboo which grow in water.
A few of my houseplants outside after enjoying a bit of late October rain.
I have been applying them both once a year in spring. Next year I’m going to start doing an application in late February/early March (I’m in Tucson where the weather warms early) & then again in July.
Worm compost on the left & compost made by a local company on the right. Both are organic.
How I apply the compost:
It depends on the size of the pot & plant. With 6″ & 8″ plants I apply a 1/4 – 1/2″ layer of worm compost & top that with a 1/2″ layer of compost. Easy does it – compost can burn houseplants if you apply too much. Floor plants get more depending on their size. For instance, my 5′ Schefflera amate in a 10″ grow pot got an inch layer of both worm compost & compost. Just water in & let the goodness begin!
Common questions regarding compost for houseplants:
Do worm compost & compost smell when applied indoors?
No. I buy both of them in a bag so there’s no odor. If I used them fresh out of bins in the backyard, there would be a smell. Even that should dissipate over time.
Can I use compost as potting soil?
No, you can’t. I always mix it in when repotting or transplanting & as a topdressing but it’s too strong to use as a straight mix.
Will worms hatch out of the soil if I apply worm compost?
No, don’t worry. Your home won’t be crawling with worms.
How do worm compost & compost work?
Both start to break down quickly but the effects are long-lasting. The roots are the foundation of your houseplants & both of these amendments help make the roots stronger & well nourished. This results in healthier houseplants.
Will my houseplants grow faster?
Honestly, I’m not sure how to answer this. My houseplants grow fairly fast because I live in a warmer, sunnier climate.
Are pets attracted to either worm compost or compost?
My kitties have no interest in either one of these. If your pet(s) is prone to digging in the soil of your houseplants, you might want to look for another way to feed them.
Word Of Warning: Both worm compost & compost nourish the soil naturally but they do help to retain water which is a good thing. This is another reason to not over do it with these amendments when applying them to your houseplants. Also, because of this, you might have to adjust your watering schedule a bit & not water as often.
My Pothos Marble Queen loves this combo!
Where to buy worm compost and regular compost:
I buy both my worm compost & compost (both are organic) at local garden centers. In case you can’t find them where you live, here are online sources:
Worm Gold Worm Compost. This is the brand I’m currently using. This one is another good option.
I use Tank’s Compost which is produced & sold only in the Tucson area. Dr. Earth’s is an online option.
My outdoor container plants get nourished with this combo and have for a long time. I use a greater ratio outdoors like 1″ of worm compost and 2-4″ of compost. It helps them better withstand the wickedly hot Sonoran Desert summers and it’s a fact that both help retain moisture. Do you feed your houseplants with worm compost and/or compost?
Houseplant Pruning Guide: How To Prune Indoor Plants
Houseplant pruning should be considered an important part of plant care. Trimming indoor plants can be done for a variety of reasons. One method that should always be done is to simply remove any dead leaves, stems, or flowers. This will discourage pests and disease. A clean plant is a healthy plant!
Another way is to actually cut back living growth on your houseplant in order to encourage a more shapely and full plant. When should you prune houseplants? How do you prune indoor plants? Let’s take a look.
When to Prune Houseplants
It is important to know when to prune houseplants because there are good times and bad times to do this task.
The best time to prune indoor plants is right at the beginning of the growing season. For most houseplants, late winter or early spring, when days are getting longer and plants are starting to wake up, is the best time.
For flowering plants, you may want to prune right after a cycle of flowering if you choose to prune. This way you will be sure not to prune off any future unopened buds.
How to Prune Indoor Plants
First, be sure to start with sterilized scissors or pruners. This will help discourage the spread of any disease. Sterilize cutting tools with either a solution of bleach and water, or you can also hold the pruner blades in a flame for several seconds.
Make sure that your pruners are sharp. If you have a dull blade, this can result in a cut that is sloppy and this can encourage pests and disease.
Stand back from your plant and imagine what a good shape would be for your plant. A good rule of thumb is not to remove more than about a quarter of the leaves on your plant. And don’t worry! You will not harm your plant by pruning. If anything, you will rejuvenate and benefit your houseplant.
If you have any leggy stems, prune those back to right about a node. A node is where the leaf meets the stem and are areas where dormant buds exist. New growth will occur at the nodes after you prune.
For softer stemmed plants, you can just pinch the growing tips as well. This will result in a bushier houseplant.
Plants NOT to be Pruned
The vast majority of houseplants can be pruned, but there are some that you should avoid pruning whenever possible; otherwise, they will not grow back. These include Norfolk Island pines, palms, and many types of orchids including the common moth orchid (Phalaenopsis). If you cut off the tops of these plants, they will not grow back.
You can, however, prune off any dead leaves safely. Just avoid trimming back the growing tip.
Winter is a great time to groom and prune houseplants
Winter is a great time to do a little houseplant tending. While it’s not the best time to repot houseplants, that’s best done in the early spring, winter is a great time to groom your houseplants and trim back any that are overgrown.
Trim and clean
Houseplant grooming can be a very relaxing job. Start by trimming any dead leaves or stems off the plant, using a pair of clean, sharp pruning shears. When removing dead leaves, be sure to also cut off the leaf petiole (stem) so you don’t leave a “stump” behind. When going from houseplant to houseplant, dip the blades of your pruners in a cup of 10 percent bleach solution or spray them with a bit of Lysol disinfectant spray to kill any pathogens that could be spread from plant to plant.
Another important step in grooming houseplants is to clean off the foliage. Use a soft, damp cloth to wipe any dust or grime off of each leaf. Leaf-shine spray products are available for this job, but they only cover up the dust rather than removing it, unless you wipe the leaves off first. Dusty houseplants receive a reduced amount of sunlight and may even have stunted growth, if the dust layer is very thick. You can also use the cloth to wipe down the stems of the plant, too.
Use a clean pair of scissors to cut off any brown leaf tips, cleaning the scissors carefully between each plant. Houseplants sometimes develop salt burn at the tips of their leaves if the fertilizer salts aren’t flushed out of the soil during the watering process. Always water houseplants in the sink and be sure at least 20 percent of the water that goes in the top of the pot drains out the hole in the bottom, taking excess fertilizer salts with it.
Another important step in houseplant grooming is to carefully inspect the plant for pests. If you spot any bumps along the stems, scale insects could be present. Look on the bottom sides of leaves for small insects such as whiteflies, mealybugs or aphids. If you spot any, wipe them off with a cotton ball soaked in isopropyl rubbing alcohol. If there’s a sticky coating on a houseplant or on the floor or table beneath it, there’s likely to be an insect infestation in the plant. A thorough inspection of the leaves and stems can confirm this.
If your houseplants are overgrown, it’s also a good time to do some trimming. Long, vining houseplants, such as heart-leaf philodendrons, pothos, hoyas and the like, can be trimmed back at any time. Removing a few of the long vines from time to time encourages thicker and bushier growth in the future.
For very overgrown, tall houseplants that have bare stems with leaves only at the top, pruning them back is a bit more complicated. Cut back only half of the stems and wait to see if they develop new leaves before cutting back the remaining branches. Some houseplants easily develop new growth after pruning while others do not. Doing it piecemeal like this will tell you which type of houseplant you have.
If the cut branches don’t sprout new leaves in a few weeks, consider air-layering the plant instead. This technique is ideal for houseplants with woody stems, like rubber tree plants, dumb cane, dracena and others. To air-layer a houseplant, nick the plant’s stem with a sharp knife about 8 to 10 inches below the terminal point of the stem. Then, you dust the cut with rooting hormone (available at your favorite nursery), wrap the area with a large handful of wet sphagnum moss, and then cover the moss with a piece of plastic wrap from the kitchen, fastening it to the stem and around the moss ball with a twist tie at either end.
Every few days open the plastic wrap and spray the moss with water to keep it moist. Within a month or two, roots will begin to form from the place on the bark that was scored with the knife. When you start to see these new roots emerging through the moss and starting to touch the inside of the plastic, it’s time to cut the new rooted piece of stem off the mother plant (just below its roots) and pot it up to live on its own.
Air-layering is one of the best ways to deal with overgrown houseplants. You’ll be able to keep all the new, smaller-statured off-sets and do away with the overgrown mother plant without any guilt.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to [email protected] or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.
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How to Prune Houseplants
In time, many houseplants will outgrow their space or become straggly and unbalanced.
Pruning and pinching creates a healthy, attractive indoor garden, encourages new growth and corrects structural problems. Done early enough, it will keep a plant the right size and shape for its space. Light trimming and reshaping can be done any time of the year, but more heavy pruning should be done during fall or spring.
Although not all houseplants need pruning, most will benefit from some attention, even if it’s simply removing dead leaves or diseased or damaged stems. Groomed plants are less likely to get pests and diseases. Cut judiciously. A good pruning job is barely noticeable. Keep in mind that it takes a long time for a major stem to be replaced, so when in doubt, don’t cut.
Houseplant Pruning Tools
Use high-quality bypass pruners or very sharp scissors. Dull pruners will crush or tear stems, leaving the plant vulnerable to disease. Poor pruning may also inhibit regrowth.
Large, woody plants, like Norfolk Island pine and Ficus benjamina, tend to require pruning. When unsure about a particular plant, consult a houseplant encyclopedia.
To shape a woody plant, proceed slowly and step back periodically to view your handiwork. Check that you are pruning it according to the natural growth habit of the plant. Shorten leggy stems or branches that have grown awry. Always make clean cuts above a node, which is where a branch or leaf is or was attached.
There are dormant buds at each node. This is where the new growth will appear. If you must remove large stems, cut as close as possible to the main stem or all the way to the base.
Pinching Back Houseplants
Many smaller houseplants are herbaceous, which means they have soft stems. Such plants require some form of pinching back to keep them dense and shapely. Vining plants such as pothos produce trailing stems that can become lanky and leggy, with long gaps between leaves. When you shorten such stems by pinching off the growing tips, this stimulates latent side buds in the leaf nodes into bushy growth.
Generally, your thumb and forefinger make good pinchers because most new growth is tender. If not, use pruners or sharp scissors. Always pinch just above a leaf node.
Some plants require regular pinching, while others need it only once or twice a year. Use care when pruning plants that flower so that you don’t cut off any buds. Get to know the flowering cycle of your plant before doing any pinching.
Houseplants to Prune/Pinch Back
Plants that do best with regular pinching include polka dot plant (hypoestes), iresine, vining philodendron (Philodendron scandens), pothos, coleus, grape ivy (cissus), tradescantia, abutilon, inch plant (callisia), creeping Jennie (lysimachia), Swedish ivy (plectranthus) and arrowhead plant (syngonium). Some flowering plants that require pinching or pruning are lipstick plant (aeschynanthus), which should be pruned back to about one-third after flowering.
To encourage reflowering in columnea, cut back older branches by one-third to one-half in spring. Other plants that may need pruning if they get too large include dieffenbachia, which should be cut back if it becomes leggy, and some of the tall-growing draceanas.
When shortening a dracaena, cut the cane at an angle so that no water will settle on the stump and cause rotting. Depending on the size of the cane you cut down, one to three or four side shoots will come up and begin growing, making it a shorter, bushier plant.
How to Water Your Indoor Plants The Right Way
Watering from below is best. Although watering from above is still the usual way people water their plants, watering from underneath is more homogeneous, less prone to overwatering and there is no concern of draining nutrients out. Plus, you can be sure that the water does actually get to the roots.
3 techniques to water your plant from below
Use a saucer. Place a saucer underneath the pot and fill the saucer with fresh water when it’s time to water. Let it soak during several hours. Empty the saucer and let the remaining water drip out. This technique is widely used by garden centers and plant nurseries to maintain humidity and keep nutrients.
Soak your plants in a tray, in a large container, in the sink or in the bathtub. Fill the bottom of it with a few centimeters of fresh water. Place you plant pots in and let them absorb water for a couple of hours. Advantage: you can water several plants at the same time. Let them dry before placing them back.
Self-watering pots. Self-watering pots are incredibly useful and time-saving. No more over-watering or under-watering, the plant does it all for itself. You just need to refill the water reservoir before it’s empty, which is approximately every other month (but varies case by case).
Watering problems are the leading cause of poor health for houseplants; here’s how to give them what they need.
There are so many reasons to love houseplants. From removing pollutants and reducing stress to increasing focus and creativity, they bring some of the outdoors inside and are, almost literally, a breath of fresh air.
But given that they were designed to live outside in the ground and in accordance with Mother Nature, if we decide to foster them inside, we have to take care to treat them well. And one of the ways in which we mess up the most is with watering.
Dr. Leonard Perry, a professor of horticulture at the University of Vermont, notes that watering, and most often overwatering, is where most houseplant-keepers go wrong. Fortunately, he writes, “it really isn’t that difficult or rocket science once you consider environmental factors, and the individual plant needs.”
And that’s a key point: Each plant has a different watering need. And not just from species to species, but also depending on a plant’s pot and potting medium, its location in the home, the weather, the season, et cetera. But once you know how to read a plant and its soil, which isn’t that hard, you can master the art of watering. Here’s what to know.
Why it’s not one size fits all
Some plants are guzzlers, others don’t need water for weeks, many are somewhere in-between – so it’s good to do a little research and see generally where each specific species falls on the water spectrum.
Further variables include:
- Potting medium (can add to moisture or dryness)
- Light exposure
- Dormant phase versus growth phase (many plants grow more during spring and summer, and want more water then)
- Hanging versus sitting (hanging plants dry out more quickly)
How to tell when a plant needs watering
With most plants, you should water when the soil feels dry to the touch. You can gently stick your finger (up to the knuckle or so) in the soil to see how dry it is. For water lovers, water when the surface is dry; for succulents and drier plants, water when most of the soil feels dry.
Also, you can lift a potted plant (or carefully tilt or nudge the pot if it’s a big one) to gauge how wet the soil is. If you get a sense for its weight right after you water, you will have a base weight to compare it to as it dries out.
If the soil is dry and the leaves are wilting, the plant is likely thirsty. But wilting (and dropping and/or yellowing) leaves can also mean too much water.
When to water
Most simply put, water according to a houseplant’s needs and growth patterns. Easy, right? Ha.
Most plants (but not all, because plants are wily things) will want more water in spring and summer, and less during their dormant period in fall and winter – you can tell their growth and dormant phases by when they are growing the most.
Because the variables that affect a plant’s thirst are ever changing, it’s best not to stick to a fixed schedule. As Dr. Perry notes, “watering on a fixed schedule may mean plants are overwatered at one time of the year but under-watered at other times.” However he does recommend a fixed schedule to check them for water.
Since soggy leaves can invite disease and fungus, the best time to water is in the morning, giving the plant the daytime to dry out. For plants by windows that are accustomed to a lot of light, be careful of overwatering on cloudy days since their foliage will not dry out at the usual rate.
(All of that said, some tropical plants love humidity and want to be misted; more on that in an upcoming post.)
What kind of water to use
Tepid. Just like you probably don’t like an ice-cold shower, your plants don’t either. Frigid water straight from the faucet can shock the roots, especially for tropical plants who spend their time dreaming of the sultry rainforest (not really, but maybe…?). You can fill the watering can when you’re done watering; when the time comes to water again, the water is perfectly room temperature – and if it’s tap water, it has a chance to dechlorinate.
Rainwater is probably a plant’s favorite, if you don’t live in a place with too much pollution, that is. Well water is usually good too, if it’s not too alkaline for acid-loving houseplants. Tap water can be great, but the salt in softened water can become problematic – and some plants don’t like chlorinated water. Finding the right water can take some trial and error.
How to water
A watering can with a long spout gives the best control for directing water all around the soil, while avoiding wetting the leaves – again, for many plants, wet leaves invite fungus.
Bottom watering – in which a plant absorbs water from the bottom instead of the top – is a great way to give your plants a sufficient drink without drenching their foliage. It ensures that those important roots near the bottom are getting enough to drink, which is harder when watering from the top.
You can add water to the pot’s saucer and let it sit, adding more water if necessary, until the soil it wet underneath the surface – then drain the water. You can also use a container that is large enough to hold the planter, and fill it halfway or so with water. If the soil feels moist under the surface after 10 minutes, remove it. If still dry, give it another 10 minutes, or long enough to get moisture to the top. Regardless of how long you let it soak, do not forget about it and let it soak all day.
The only problem with bottom-watered plants is that it doesn’t remove excess salts from the soil like top watering does. Easy solution: Top water your bottom-watered plants once a month or so.
Remember to aerate your soil
Since a houseplant doesn’t have the benefit of worms and other creatures to aerate the soil, its humans need to poke some holes in the soil from time to time – allowing the water get to where it needs to go. This helps “break up dry pockets of soil, ensure even moisture distribution, and get airflow to the roots,” says Darryl Cheng of the popular Instagram feed, houseplantjournal, and keeps “the soil structure healthy until the next time your repot the plant.”
See more here: Why your houseplants need soil aeration
How much water to use
Some plants naturally may want less water, like cacti, succulents, and plants with thick leaves. Most of the rest like to drink. And remember, they usually want drinks, not bitty little sips. Add enough water so that water comes out of the drain hole – you want all the roots to get wet, and enough water to flush out salts.
If the potting medium is really dry, it has a harder time absorbing the water – so if water runs out the bottom surprisingly quickly, it is probably passing right through. In this case, give the plant a long, slow drink to allow the soil to absorb it.
For really dry plants, you may notice that the soil has dried up enough to create a gap between the edge and the pot – in this case, gently nudge the soil back into place so that the water doesn’t have an escape route straight down the side.
What to do after you water
Many plants root systems have a bit of a Goldilocks syndrome – they want not too little, not too much, but just the right amount. It’s not that exact, but one thing is certain: Most do not appreciate being forced to sit in their water for too long. Not only do they begin to soak the salt back up, but staying too wet can lead to rotting roots.
For a pot that sits inside of a decorative pot without a drain hole, make sure that the outer pot is not filled with water after watering. (I learned that one the hard way … sorry, my beautiful string of pearls! At least I figured it out before it was RIP time, but still, it wasn’t pretty.) So check after 30 minutes and dump out any water from the outer pot.
If you pot sits on saucer, also check back after 30 minutes and dump any lingering water out of the saucer. This give the plant enough time to get a little extra watering from the bottom, but not enough to lead to over-wetness problems.
Getting to know your plants
The trick really is just getting to know a plant. It’s the reason that I add plants one by one, despite my plant lust at the nursery. But when all else fails, fight the urge to nurture with abundance. As Dr. Perry writes, “The best advice is that if in doubt about whether to water or not, don’t. It is better for plants to be a bit dry, than too wet.”
Sources: My brain (no link available, phew); University of Vermont Department of Plant and Soil Science; Better Homes & Gardens; Gardening Know How.
- Leave room for water in the pot! When you’re repotting your plants, don’t fill the pot up the rim with potting soil. This makes it much harder to water as you’ll have to dribble water over the soil and wait until it seeps in. Leave enough room that you can pour in some water and let it soak in on its own.
- Be consistent. Even if this means marking days on your calendar, make sure your watering habits are consistent, so the plants don’t suffer through debilitating cycles of drought and plenty. Although each species is different, in general plants, prefer even moisture.
- Keep like with like. If it’s possible, grow similar plants next to each other, so you won’t have to thread your way among various plants while watering. Keep your succulents with your succulents and your aroids with your aroids
- Learn to water from the bottom. Bottom watering is a very effective method for many plants whose leaves don’t like to get wet.
- Use a long-necked watering can. This will allow you to apply water precisely at the soil level, without wetting the leaves. Fungal disorders are encouraged by wet foliage.
- Never let your plants sit in water! Unless they are bog plants, make sure to empty the plant trays after you’re done watering so the plants aren’t sitting in water. Sitting in water is a good way to get root rot, while is frequently lethal.
- Keep a water supply nearby.
- If your plants aren’t near a water source, make your life easy and hide a watering container somewhere in the room where they’re located. This will make it easier to regularly water.
- Provide drinks, not sips.
- Shallow and insufficient watering encourages weak root systems and makes the plant more vulnerable to collapse. When you water, make sure you do it thoroughly, so water runs through the container. This also helps flush out fertilizer salts, which can be dangerous if they accumulate.
- Water in the morning. Watering at night encourages dampness, which is a prerequisite for fungal attack. Instead, water during the day, when the evaporation and transpiration rates are at their best.
- Lastly, pay attention to water quality. Some plants cannot tolerate chlorinated tap water, while other plants have a difficult time with soft water. Use the cleanest water possible, such as rainwater, water that has been left out for a few days to dechlorinate, or reverse osmosis water.