Garden Myths – Learn the truth about gardening

Online information about growing clematis from seed is limited. As a result, I decided to investigate clematis seed germination in more detail by running 120 test cases on a number of different types of clematis. This report summarizes known information and presents new information found as a result of this work.

How To Germinate Clematis Seed – Clematis Houldine (not from seed), by Robert Pavlis

Growing Clematis From Seed – Current Information

My go-to sources for germination information on all types of seed are Dr. Deno’s Seed Starting Books (Deno), and Ontario Rock Garden And Hardy Plant Society web site’s Germination Guide (ORGS). Dr. Deno’s books are available as a free download – see the above menu called Free Books for details. These are the two best sources of information on the internet. Both of these have some general guidelines for clematis, but the information is not very detailed and for some species the two sources disagree with each other.

These sources provide information on a per species or cultivar basis. In some cases cold stratification is required, and in others it is not required. In some cases a warm period is followed by a cold period and then a warm period again. What is clear is that different species require different methods.

There is also a website, developed by Brian R. Collingwood with the title Clematis From Seed (CFS), but the information there is extremely difficult to extract. The method used most by this author is to pot up the seed, place it in a greenhouse and wait. Germination conditions are only provided in a very general way. The site reports that cold stratification is not required but fall collected seeds seem to spend the winter in the cold greenhouse.

The International Clematis Society (ICS) says “Clematis seeds may take up to three years to germinate, but you should get some germination in about six months to a year. Collect ripe seed in the fall and plant in sterile seed starting mix, covering seeds with a thin layer of sand. Place the container into a zip lock polyethylene bag and place it outside in a shady spot (or a refrigerator) for several months during the winter so that they go through several freeze/thaw cycles. Then place the covered container in a warm location out of direct sunlight and wait for your first seedling.”

The stated requirement for stratification by ICS contradicts the recommendations by Deno, and ORGS for some species. No other references suggest that a ‘freeze/thaw cycle’ is required.

The British Clematis Society (BCS) suggests essentially the same procure as ICS. They put the pots in a ‘cold greenhouse’ without defining what that means. It is not clear if they feel stratification is required.

I have had fairly extensive experience germinating perennials, shrubs and trees from seed but have had limited experience with clematis; germinating a half dozen species/cultivars.

In summary, after looking at all of the available information I came to the following conclusions.

  • Good detailed and reliable information for germination is not available
  • It is not clear if and when stratification is required
  • Documented methods use pots, mostly in greenhouses. Newer germination methods, more suitable to homeowners are not discussed, except in Deno.
  • Germination periods are long, and yet the effects of GA3 have had limited testing.

Clematis Germination Procedures

Seed was obtained from ORGS, who were kind enough to provide left over seed from their very popular annual seed exchange. This seed originates from many amateur growers and so there is a possibility that (a) seed may not be viable, and (b) they may not be named correctly. There is no way for me to verify seed names.

A literature review was done for each type of seed to determine the best germination procedure. Using this information, a set of germination conditions was defined for each seed type.

The standard reference method was the baggy method at room temperature and this method was included for almost all seed types. Other germination methods could then be compared to this standard method to see if they provided an improvement in germination.

How To Germinate Clematis Seed – baggy method, by Robert Pavlis

Each method was given a short hand code of the form: a number followed by a B or W to indicate the Baggy or Water method (described below). This was then followed by one or more of the following codes to further define the method:

W – warm (room temperatures throughout the process)

D – dark throughout the process

WCW – warm, cold (5C), warm cycles, with a temperature change every 30 days

CWC – cold, warm, cold cycle, with a temperature change every 30 days

N – nude (outer seed coat removed after several days of soaking)

GA3 – treated with GA3 hormone.

T – tail left on the seed

The initial number is a sequential number indicating the seed type. Each unique species/cultivar, from a unique source, was given a unique number.

For example “5BWTGA3” would be seed type #5, treated using the baggy method, in warm conditions, with tails left on, and treated with GA3.

The seeds were checked on a weekly basis, and germinated seed was counted and removed. Moisture levels were maintained throughout the process. Any molded seed was not removed but mold was not a significant problem except as noted.

Ten seeds were used for each test case. Seed was selected so that each test case, for a particular type of seed, had similar sized seed.

GA3 treatment was done at the start of the process. For the baggy method, I used the method outlined by Deno. For the water method, the GA3 was added right to the water in which the seed was floating. The GA3 water was not replaced with fresh water since GA3 will break down over time.

Seed coat removal was done after several days of soaking in water. The process is tedious and very difficult for tiny seed. On very small seed or on seed that held the seed coat very tightly, only part of the seed coat was removed.

Germination Methods

One of the main reasons for conducting this study is to compare some common germination methods.

Most of the references reported above use the ‘potted’ method. Seeds are placed in a pot of soil, covered with grit, and left until they germinate. This method works, but it has one serious drawback. Since germination is very slow, you end up with a lot of pots, waiting for something to happen. For people who germinate many types of seed this is not a very practical method.

The method I have been using for several years is the baggy method. Seeds are placed inside a Ziploc plastic snack bag, along with a moistened paper towel. Over the test period the paper towel is kept moist. In my case, I am using well water that is on the hard side, but any water source should work. Using this method, a large variety of seeds can be stored in a small space which can be very important when you keep them in the fridge. I have used this method to germinate hundreds of species.

A second method, which I will call the ‘water’ method, is reported by amateur clematis growers in a few locations on the internet. Seeds are placed in water until they germinate. They are actually fully submersed until germination.

Some preliminary testing last year with old clematis seed showed that the method can work, and that viable seed does not rot in the water.

Another method that has been reported is the ‘nude’ method. The outer coat of the seed is removed at the start of the process. The inner part of the seed is left to germinate. Some preliminary testing showed that this can also work and some people report that it speeds up the germination process.

Test cases were selected to compare the baggy method to the water and nude methods to see if one of these produced higher germination rates, or faster germination.

Baggy Method vs Water Method

In all except one case, the baggy method worked as well as the water method. C. virginiana had better germination using the water method, but it also required GA3 to germinate. It is quite possible that the longer exposure to GA3 in the water method improved germination.

Results – Does Removing the Seed Coat Work?

Removing the seed coat did not improve germination for the water method. Visually, a lot of these seeds got coated with slime (bacteria?) and seemed to slowly decompose. Most water+nude tests were stopped in October because of decay.

Not enough test cases of nude seed in baggies was carried out to come to any conclusions.

Removing seed coats does have one advantage. In a couple of cases removing the seed coat make it clear that the seed was empty and not viable. This would save time trying to germinate such seed. However, removing the seed coat is tedious and time consuming. It is also almost impossible on very small seed – at least for my big fingers!

Clematis Germination – Cold Stratification

It is not clear if stratification is required. Both Deno and ORGS recommend it for certain species, but not others. ICS and BCS suggest it is required for all species, and CFS says it is not required for any species. I have successfully germinated clematis in the past without cold stratification, so it is certainly not a requirement for all species. It may however speed up the germination process.

Since the two most trusted resources, namely Deno and ORGS, suggest that stratification is not always required, this study investigated the need for stratification in only those cases were at least one of these reference sources indicates it is required or beneficial.

Results – Cold Stratification

As a general rule cold stratification does not seem to be a requirement. For some species it is either required, or helpful.

C. orientalis had poor germination with WCW cycling and no germination without a cold treatment, but the differences may not be statistically significant. Deno and ORGS both report that C. orientalis germinates warm.

There were two sources of C. stans. One source showed good germination with CWC treatment, and no germination warm. The second source showed good germination with CWC treatment, and reasonable germination warm.

Some non-clematis seed germinates in the cold but this was not observed with clematis, except for 1 or 2 seeds. Any cold treated seed did not germinate until it was returned to warm conditions. This observation contradicts Deno’s report that some species germinated better cold, but the tested species list in the two studies has some overlap, but are not the same.

Clematis Germination – Tails

Most of the references do not mention the need to remove the tail on seeds. ORGS recommends removing the tail because it might interfere with germination. It is known that some other non-clematis seed can be prevented from germination when tails are left off (or is that a myth?).

Most of the seed obtained for this study did not have tails in tact and could therefore not be used to investigate this phenomena. Where tails were present, trials were conducted with and without tails to see if there is an effect.

Results – Should Tails Be Left on Clematis Seed?

In the few cases that have results, the presence of tails did not stop germination, but may have lowered germination rates slightly for some species.

Based on limited data, it seems that the tails do not significantly affect germination.

Clematis Germination – GA3

GA3 is a plant hormone that has been used to speed up the germination process. http://botanicallyinclined.org/the-magic-of-germination/

Very little testing seems to have been done using GA3 on clematis. ORGS does mention it for some clematis species, and Deno suggests “GA3 or light is a requirement for some species”.

GA3 has reduced the time of germination for some non-clematis cases for the author.

Results – Does GA3 Treatment Help?

GA3 hormone treatment was only applied to a few species where the literature suggests it would be helpful or required. Test results show that it is required or at least helpful for C. pitcheri and C. virginiana.

For non-clematis seed, GA3 tends to speed up germination, and so both of these seeds may still germinate without treatment.

Most of the GA3 seedlings were grown on to see if the hormone caused any abnormal elongation. No problem was identified.

More testing of GA3 on clematis seed is warranted.

Clematis Germination – Darkness

It is not clear from the references if darkness is a requirement. It is suggested for some species by Deno and ORGS, but the other references do not mention it as a requirement.

Results – Do Seeds Need To Be Dark?

The only two species that were tested in the dark were C. viorna and C. viticella and in both cases there was some improvement in germination when done in the dark. As I write this, C. viticella ssp campaniflora (23BDWCW) is germinating well (50%, mostly in November), and the same seeds in light are not germinating. The number of test cases was limited and germination rates were low.

Any time spent in the cold would be time spent in the dark since the seeds were stored in a small bar fridge.

Further testing in the dark is warranted.

Clematis Germination Results – General

The experiment was started at the end of February 2015. To see the detailed results click on this link: Growing Clematis from Seed 2015.

This file will be updated from time to time until the end of the test period. Last updated on Nov 16, 2015.

In general, clematis seed is very slow to germinate, which is in agreement with other references. After 8 months 30% have not germinated or have had very few seeds germinate. In most cases germination is spread over many weeks or even months. Only a couple of species germinated quickly.

The baggy method works as well as or better than the water method. I see no reason to use the water method.

Germination by the baggy method was not compared to the pot method. However, since most clematis do not seem to need cold stratification, it is possible that the baggy method will result in quicker germination in northern regions because seed is not sitting outside in the cold all winter waiting for warm weather.

Based on all of the references and the current tests, I would recommend the following as a general germination procedure for most clematis. Use the baggy method, warm, in the dark, with tails removed. If you have GA3 use it, but it is probably not required.

Conclusions – Species Specific

Based on this study I would make the following recommendations. Where my conclusions differ from Deno or ORGS, I have added a note.

  1. fusca – easy to germinate warm
  2. ispahanica – easy to germinate warm
  3. crispa – easy to germinate warm (both Deno and ORGS suggest C-W-C-W cycles and say germination is prolonged. Could my seed be something other than crispa?)
  4. virginiana – requires GA3 and warm (Deno suggests warm and light or GA3, ORGS suggests just warm. Personal communication confirms that fresh seed germinates warm without GA3)
  5. pitcheri – may benefit from GA3 and warm (Deno and ORGS suggest a warm-cold cycle)
  6. orientalis – easy to germinate warm
  7. viticella – warm and dark (Deno – warm and light with no germination in the dark, ORGS – warm-cold cycle followed by 10C for germination. It is quite possible that my ‘viticella‘ were not pure species since the term is used as a general term for un-named hybrids as well)
  8. integrifolia – easy to germinate warm
  9. stans – try warm for 2 months and if no germination give a cold treatment (ORGS suggests a cold-warm cycle)
  10. heracleifolia – easy to germinate warm (ORGS suggests a cold-warm cycle)

The following are some results from prior years. The baggy method was used for these as well.

Clematis hirsutissima – exposed to outdoors in late winter, followed by several warm –cold cycles. Took a year to get some germination.

Clematis integrifolia ‘Mongolian Bells’ – easy to germinate warm.

Clematis alpina ‘Willy’ – a cold-warm-cold cycle produced very low germination rates.

  1. Dr. Deno’s Seed Starting Books
  2. ORGS – Ontario Rock Garden & Hardy Plant Society, Germination Guide
  3. Clematis From Seed
  4. International Clematis Society – Germination from Seed
  5. British Clematis Society

If you like this post, please share …….

Starting Clematis from Seed

To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video

Looking for a way to expand your clematis, or should I say as some prefer KLEM-a-tis collection? Try starting new plants from seeds this summer.

Once the seedheads turn brown, shake out the seeds and collect the fatter, swollen ones for propagating. Remove the feathery attachments.

Pack the seeds in a plastic bag filled with a mix of equal parts of perlite and damp peat moss. Place in the refrigerator for at least three months.

Plant the seeds in a flat or shallow container filled with a seed starting mix or mixture of equal parts damp peat and perlite. Keep the soil moist and move the flat to a sunny location as soon as the seedlings appear.

Be patient, it can take up to several months for seeds to sprout. Transplant the seedlings into individual pots, once they have at least one set of true leaves.

Your new plants may not look like the original, but the surprise results add to the fun.

A bit more information: You can also expand your collection while maintaining the clematis’s original features by layering. This method helps the plant form roots on the stem, while still attached to the parent plant. Listen to my Melinda’s Garden Moment audio tip on this topic for more details.

Tags

seeds clematis

How To Grow Clematis

First- Don’t worry! Clematis are not as hard to grow as you may think. They are easier to prune than you think, too! Follow the simple guide below to help you get started and to tell you about some really neat ways to turn your Clematis Vines into beautiful features in your garden!

For Beginners- Nothing is more satisfying than seeing your efforts pay off with a plant covered in flowers year after year! Clematis can be a part of any size garden and they live for very many years. However, you may have heard that they are difficult to grow. You may have heard that they require complex pruning to bloom each year. Let me assure you that you don’t need to be intimidated by this beautiful vine. Most varieties are vigorous, hardy and easy to grow. There are a few finicky varieties in the Large Flowered Types, but you can start today with some very rewarding varieties listed here: Clematis viticella Polish Spirit is our favorite of this type. It blooms heavily in summer with rich purple flowers similar to Clematis Jackmanii (the most famous variety in the world). Just plant, mulch and water as you would other plants in your garden and prune it back to about two feet each spring. Clematis montana Rubens is a wonderful vine in flower as well as in foliage! Each spring the vine is covered in rich pink flowers with an unmistakable vanilla scent. The leaves emerge with a bronzy-purple color and mature to a deep green. This one is even easier than the others to grow. Don’t bother to prune it at all except when you want to shape it up a bit. So, there you have three great varieties that bloom in three different seasons and have three different colors! Why not try all three? Don’t think you have the room? If you have an old fence or mailbox you’d like to spruce up, you’ve got the room. You can also combine them with your other garden plants. Read the section below on Training for more great ways to use your Clematis vines!

Planting- Since Clematis live up to 50 years or more, you should take the time to plant each one carefully. Water the pot well before planting. This is an important step for any planting. Once you have selected a location, dig a hole at least twice as big as the pot and twice as deep. In areas with poor drainage, consider a larger hole or mounding up from the ground a bit. Mix some of the soil from the hole with a good topsoil and compost if you wish. The exact proportions will vary by your soil conditions. Backfill some of the hole with this mix. You may gently tease some of the roots away from the sides but be gentle.

Place the clematis on the backfill and look at the soil line of the plant and the ground. The clematis should be about two inches lower than the ground. This keeps the roots cooler and provides buds below ground if the vine should suffer a disease or infestation and you need to cut it back. Every clematis we sell has buds below the soil line, but we’d like you to plant deeply for extra protection. Fill the rest of the hole and over the top of the pot’s soil line with the mix you made earlier. Don’t cart the extra away until after you water the plant thoroughly. Sometimes the settling soil can leave the vine exposed. After all filling and watering are done, you should mulch your clematis carefully. This can be done with composted pine bark or other mulches, but you can also use stones. This is important because clematis need ample moisture to grow their best and mulch can help the soil retain moisture. Also, be sure to go back and water new plantings regularly during the first growing season. This will help them get off to a great start!

Some clematis will establish very quickly and flower within a year of planting. Others take a little longer, but they’re worth the wait!

Training- Some folks think of mailboxes and lampposts when they consider Clematis. These are two great ways to feature your vines. However, over the centuries gardeners have found dozens of beautiful ways to add Clematis to their gardens. A trellis is certainly a way to get a Clematis to cover up a bare wall or an unsightly view, but they can just as easily be trained into a shrub! Try a summer flowering variety like Clematis Comtesse de Bouchaud to add life to a forsythia whose spring show has long since faded. Or try combining complimentary colors like Clematis Candida and red roses! You can even mix different colors of Clematis together for a great show or to extend flowering season. No matter where you grow them all they need is a little guidance and the occasional twist-tie secured loosely until the vine grabs on by itself.

Some types of Clematis aren’t vines at all and can find a good home in your perennial border. Clematis integrifolia is a cute perennial with lovely blue flowers that would look great anywhere. Clematis heracleifolia is a stout, almost shrub-like perennial that also flowers blue and has leaves with a great texture. Clematis mandschurica is a rare cousin to Sweet Autumn Clematis that is a perennial with the same starry white flowers as its bigger relative. But don’t leave the perennial bed yet! The British are known to allow even the vining types into the border. They let them (sometimes with a little guidance) scramble around the perennials like streamers filling in the open spots. Clematis Nelly Moser would be excellent for a partly shady perennial combination. You can even use Clematis as a ground cover!

There are plenty of ways to grow Clematis on structures in your yard. Try training a Clematis Ernest Markham up each side of your front door. Sweet Autumn Clematis would provide summer shade overhead on a lattice over your back door. The old fence would brighten right up with a Clematis montana Grandiflora draped over it. Imagine your plain old bushes with a splash of red Clematis Madame Julia Correvon or your dogwood brought back to life in late summer with white flowered Clematis vitalba.

Many of the Large Flowered Types make great container plants as well. Try Clematis Dr Ruppel in a big pot on your patio or deck. You can plant small annuals around the base of the pot, too! Clematis General Sikorski’s blue flowers look great combined with white flowered impatiens or petunias. Just remember to use a large container, mulch your Clematis and be sure to remember to water it regularly.

The possibilities are only limited by your imagination! Look around your yard with these ideas in mind and I’m sure you’ll find lots of ways to use the “Queen of Climbers”.

Pests- Clematis can get many of the same pest infestations as your other garden plants. Light infestations of insects and mildews can be treated with sprays suggested by your local garden center. A heavy infestation may be best treated by hard pruning of your vine. Landfill or burn the pruned parts. Do not throw them into the back corner of your yard or compost them. Slugs can be a problem on young vines at times. Encourage toads to live in your garden by providing them with cover or set a low jar of beer a couple of feet from your vines. There are chemical baits available for them as well. Usually the problems are minor and a little care is all you need to return the vine to its full beauty. The only major disease affects the Large Flowered Types and is called Clematis Wilt. When a vine is infected, one or more stems mysteriously wilt and die. If this happens, cut several inches below the dead stem or stems with sanitized pruning shears and landfill all of the debris. If the entire vine is infected, trim it to the ground. This is one of the reasons they should be planted deeply. New buds will arise from the crown underground. If you continue to have problems with Wilt or live in an area known to be badly affected by it, consider many of the fine species like the viticellas, alpinas and montanas. They are highly resistant to Clematis Wilt.

Pruning- OK, now, don’t worry! This is easier than you think. There is a very simple rule to follow when pruning your Clematis. Just use the flowers as a guide. Clematis flowering is divided into three major groups: spring (1), early summer (2) and late summer/fall (3). If you know when it flowers, you can choose when to trim it. There are also ways to make some of them change their bloom time, but that gets more complicated and I promised simplicity!

Group 1 Clematis flower in spring on buds from last year’s growth. They actually don’t need to be pruned at all but you may want to tidy them up from time to time. The best time to prune them is just after flowering. Shape them up or remove crowded or damaged branches. You can also guide new growth to a new position by trimming and tying branches at this time.

Group 2 Clematis begin flowering in early summer from last year’s growth as well as flowering later on short canes from new growth (in most cases). These should be pruned in spring before new growth begins. Look for fat, healthy buds on sturdy branches. They usually begin 1 to 2 feet down from the top of the vine. Make your cuts just above these healthiest buds. You may notice that you are cutting away some healthy canes, but you will be giving preference to the buds that will produce the best growth and flowers for you. At this time, trim away crowded and damaged branches, too.

Group 3 Clematis flower later in summer and into fall. They form flowers on new growth each year. For the best display and neatest look, they should be pruned back hard each spring to about two feet off the ground. However, if you are training one of these into a tree or onto an overhead arbor they should be left much longer. Look for fat, healthy buds on sturdy canes and make your cut just above them. The branches may be guided and tied to new positions now also.

Herbaceous Clematis don’t fit into the 3 groups mentioned above. They die back to the ground every year and all dead growth should be removed. They should be handled the same as perennials. The exception to this is Clematis heracleifolia which will die back to about 6 inches. Find the buds swelling in spring and trim just above them.

No matter which Clematis you choose, they will bring many years of beautiful blooms to your garden! Many can even be cut and used in arrangements or put in a vase. Try floating several in a shallow bowl for an interesting centerpiece. Their beauty and versatility truly make Clematis the Queen of Climbers!

On our site, Clematis are listed with updated hardiness guidelines. The American Clematis Society has made great progress recently in disproving the traditional hardiness limits used in most literature. Based in hot, Southern California, they have been successfully growing most varieties with beautiful results!

There are also many ways to extend the northern range of Clematis. Heavy mulching and/or planting in protected locations can raise the hardiness limit by a zone or more. Use a south facing wall with winter sun to create a slightly warmer climate in your yard.

So, relax and enjoy the site. And remember, anywhere we ship, there are Clematis for you!

George Weigel Purple clematis is a favorite flowering vine in central Pa. They’re best transplanted in early spring, although early fall is OK, too.

Q:

My father-in-law recently passed on, and we are in the process of cleaning out his house. I noticed yesterday a gorgeous clematis, dark purple, growing on the east side of his home. My husband remembers it being there for a long time. I would like to transplant it at my own home but am unsure how to go about that. Any help is appreciated. It would be a great way to remember my in-laws.

A: Clematis can be transplanted, but the best time to do it is in late winter or early spring, just before new growth starts. September or early October is another OK time.
Either way, start by preparing the new site at your house. Dig a generous area (the bigger the better) and work an inch or two of compost into the soil. I’d also work in a few handfuls of granular organic fertilizer such as Espoma’s Plant-tone and a scattering of mycorrhizal fungi (root-helping fungi sold under a variety of brand names in most garden-center fertilizer sections these days).

Before digging out the clematis, cut it back to about a foot. With a sharp spade, start out about a foot out from the base of the plant and work your way down and around, down and around, down and around, until the plant loosens. Clematis are pretty deep-rooted, so go down and try to get as much of the root system as possible.

Wrap the excavated plant in burlap or wet newspaper during the move and get it back into the ground at your place ASAP. Plant it just a hair deeper than it was – about an inch below grade to encourage new shoots to sprout from the roots. This is an exception, by the way. Most woody plants should be planted at grade or slightly above.

Cover the ground with about 2 inches of bark mulch, making sure to keep the mulch a couple of inches back away from the stem so as not to rot it. Then give the plant a good soaking and keep the ground consistently damp the first full growing season. Basically, treat it like a new plant.

One other thing you might want to consider if this is a particularly sentimental plant – take a few cuttings before moving the plant. New clematis can be started by cutting a few branch tips (early summer is the best time) and rooting them with a rooting hormone in potting mix. Layering is another way to get new plants going in early fall. If you can get a few “babies” started, that’ll be some backup insurance in case the mother plant doesn’t survive the move. Layering involves pinning a nicked section of branch to the ground to encourage roots to grow from that section.

PROPAGATING OR MOVING AN OLD CLEMATIS VINE

QUESTION: State: WA

I have a huge, and obviously very old, clematis that has grown up the side of my house. The woody trunk is about 3 inches in diameter. I would like to move this magnificent plant to a new location.

What’s the best way to move it? What time of year should I do it? How much of it should I cut back before moving it? What else do I need to know to ensure that the plant flourishes once relocated? Many thanks for any advice you can offer.

ANSWER: The best way to get clematis in a new area is to purchase one. Moving such an old vine will be very difficult.

Instead of trying to move such an old clematis right away, I suggest taking cuttings from an area that hardens off this summer. This will give you backups of the vine if it doesn’t survive the trauma. There is a very good chance it will not survive a move.

Take a piece of vine that is either this spring’s growth or later in the summer, growth that has stiffened a little. Cut the vine into pieces with two strong buds at the top and two buds at the bottom. The buds are just above the leaves on the stem. Don’t use spindly, wimpy end growth. A long piece of vine should give you several cuttings with buds at each end.

On each cutting, cut off all but one of the leaves at the top, and trim that leaf by cutting it in half. Make sure you do not injure the growth buds.

Dip the bottom end in a rooting hormone and pot it into a small, 4 in, sterilized pot filled with sterilized potting mix. Remove the bottom leaves. Plant the cutting with the bottom leaf nodes and buds below ground. Water it well.

Cover it with a mason jar or a plastic domed lid. Make sure the cover does not touch the leaves or vine. Set it in the shade in your garden. After 8 weeks, gently tug on the stem to see if it has rooted. If it has, move it into a larger pot. Plant it out in the garden the following spring.

Be sure to read the article, PROPAGATION-AIR LAYERING, at the GardenSMART ARTICLES page.

To move your large clematis vine, look for suckers with roots, young growth that you can detach from the main vine. Cut through the connecting tissue, dig, and move these in the late winter/early spring.

After you have as many backup vines as you can get, only then cut the vine back to just above its last set of leaves (two sets would be better) but no shorter than 24 inches above ground.

Dig your main vine with as much of the root ball as you can get. Plant it in your new area at the same depth it was growing. Be careful not to injure any shoots that might be below ground.

Keep the newly planted old vine well watered every day. Even then, the move will most likely not be successful. If it is, it will take several years to begin vigorous growth.

Trimming or Transplanting Clematis – Knowledgebase Question

Spring is the best time to move your clematis and you’ll probably want to prune it back to make it easier to move. With that said, each type of clematis has its own preference when it comes to being pruned. After you’ve dug and transplanted your clematis, you’ll want to maintain it with annual pruning.
The earliest flowering clematis bloom on old wood, while later flowering types must produce new growth in order for flower buds to form. Group A: are early-flowering clematis. Plants in this group bloom in early spring, generally in April and May, from buds produced the previous season. Prune these plants immediately after flowering, but no later than the end of July. This allows time for new growth to produce flower buds for the next season. Remove shoots that have bloomed. You can prune out more vines to reduce the size or to form a good framework of branches, but avoid cutting into woody trunks. Plants in this group include: C. alpina, C. macropetala, C. armandii, C. montana and C. chrysocoma.
Group B are large-flowered hybrids. These bloom in mid-June on short stems from the previous season’s growth and often again in late summer on new growth, though these blooms are usually smaller. Prune these types in February or March by removing dead and weak stems, then cut back the remaining stems to the topmost pair of large, plump green buds. This cut could be a 6 inches to 18 inches from the stem tips. Plants in this group have the tendency to become leafless at the base as they mature. You can underplant with low, spreading perennials to help conceal the stems. You may be able to force a flush of new growth from the base by cutting the vine back to 18 inches immediately after the flush of bloom in June. Plants in this group include: ‘Nelly Moser’, ‘Miss Bateman, ‘Lasurstern’, ‘Duchess of Edinburgh, ‘Mrs. Cholmondeley’ and others.
Group C: are late-flowering clematis and plants in this group flower on the last 24-36 inches of the current season’s growth. Some types begin blooming in mid-June and continue into the fall. This is the easiest group to prune since no old wood needs to be maintained. In February or March cut each stem to a height of about 24-36 inches. This will include removal of some good stems and buds. Eventually the length of the bare stem at the base will increase as the vine matures. Plants in this group include: C. viticella, C. flammula, C. tangutica, C. x jackmanii, C. maximowicziana, ‘Perle d’Azur’, ‘Royal Velours’, ‘Duchess of Albany’ and others. Hope this information helps.

How to grow Clematis

Latin Name Pronunciation: klem’uh-tis

This very diverse group of lovely, ornamental vines will entice you to garden on the vertical plane. There’s a Clematis for virtually every situation: grow the shorter and non-climbing types through shrub Roses and small trees and cover an arbor or a trellis with the taller varieties. The long flowering season begins with the compact alpinas and macropetalas in early spring, progresses through early summer with the large-flowered hybrids, continues through late summer with the boisterous texensis and viticella varieties, and concludes with the exuberant and infallible Clematis paniculata that will literally cover an unsightly structure or arbor in one season.

By entering your email you will receive a link via email to download our free eBook “How to Design Your Garden.” You will also be subscribed to receive email from White Flower Farm.

Light/Watering:

  • In general, these lush vines like at least 6 hours of sun. Some varieties are adapted to partial shade and all benefit from afternoon shade in the South.
  • Clematis prefers a cool root run, so lay flat stones at its base, or plant annuals or shallow-rooted perennials around them.
  • Regular watering is desirable, especially during seasonal dry periods. Clematis is deep-rooted, so water thoroughly.

Fertilizer/Soil and pH:

  • Clematis is at its best in rich soils with good drainage. It prefers a neutral soil, so check pH and add lime if needed.
  • Dig a generous hole and amend soil as conditions indicate, avoiding fresh manures.
  • Plant the crown of your plant 3–4″ below the soil surface; this will protect dormant buds that will provide new growth if the existing stem(s) are injured.
  • Provide support immediately or plants will languish.
  • Clematis is a heavy feeder; supply a low nitrogen fertilizer such as 5-10-10 in spring, when the buds are about 2″ long. Alternate feedings every 4 to 6 weeks with a balanced 10-10-10 fertilizer. Continue this alternate feeding until the end of the growing season.

Pests/Diseases:

  • Clematis is susceptible to fungi that can cause the vine to suddenly wilt and turn brown or black. Carefully prune out all diseased tissue and destroy; disinfect your pruners with a bleach solution. Generally this disease is not fatal, especially if you have planted the vine correctly, as dormant buds will send up new growth from the crown.
  • Handle gently when planting and be careful when cultivating, as physical injury to the stems can cause them to wilt and die.

Companions:

  • Plant these lovely vines at the base of shrubs and small trees; they will weave their way through the supporting foliage and extend the season of interest with their showy blooms.
  • Use the woody structure of Shrub Roses to support the non-clinging Clematis varieties; for instance, grow purple or blue Clematis through a yellow Shrub Rose for a fabulous contrast. Remember that a supporting woody plant will compete with the Clematis for water and nutrients and adjust your culture as necessary.

Reflowering:

  • To promote reflowering for late season bloomers during the growing season, the vine can be cut by one-half after the main bloom period.
  • Varieties that flower on old and new wood will often throw out a few blooms at the end of the growing season.

Transplanting:

  • Young vines may be moved with plenty of soil as long as they are watered religiously.
  • Depending on variety, cut back lightly or severely before moving in early spring.

By entering your email you will receive a link via email to download our free eBook “How to Design Your Garden.” You will also be subscribed to receive email from White Flower Farm.

Pruning:

  • Dead or damaged stems may be removed at any time.
  • Early in the first spring after planting, prune the stems of all Clematis varieties down to the lowest pair of healthy buds. Thereafter, prune to control size and shape or to encourage more profuse bloom.
  • Flowering tends to decline on stems that are four or more years old, so it’s a good idea to prune out very old stems periodically in early spring. This pruning helps produce more compact plants with flowers closer to eye level. Sometimes, on older vines, the flowering is confined to a small area at the tops of the stems.
  • If you wish, you can rejuvenate old plants by cutting them back severely, to about 18″. Wait until after the first flush of bloom to perform the surgery.

Clematis are divided into pruning groups as follows:

Group I plants bloom on old wood and require no pruning except to control size, in which case prune lightly after flowering back to a pair of healthy buds. Group I varieties include Clematis alpina ‘Stolwijk Gold’ and Clematis montana ‘Mayleen.’

Group II plants bloom first on old wood and then again on new; prune lightly in early spring to shape and remove weak growth and then prune after bloom if desired.

Group II varieties include:

Group III plants all flower on new growth and can be cut back to 12″ in early spring. This group is ideal for growing through shrubs as all old growth is removed annually.

Group III varieties include:

End of Season Care:

  • Plants may be mulched, but take care to keep mulch material away from the crowns and stems of the plants.
  • Check to make sure that the vines of Group I and II plants are tied securely to supports to withstand winter winds.

Calendar of Care

Early Spring:

  • Fertilize with 5-10-10 when new growth reaches two inches.
  • If you need to move a plant, transplant young vines now.
  • Wait until new growth appears before removing dead or damaged stems and before pruning as required by variety: leave Group I Clematis alone; prune Group II plants lightly to shape and remove weak growth; cut Group III varieties back to 12 inches above the ground, or higher if you desire taller vines.
  • If this is the first spring after planting, prune stems of all varieties down to the lowest pair of healthy buds to encourage strong growth and new stems.

Mid-Spring:

  • Continue feeding every month, alternating 5-10-10 with 10-10-10.
  • Plant annuals at base of plants if unprotected by flat stones to allow for a cool root zone.
  • Gently tie vines to supports as they grow.

Late Spring:

  • Mulch if desired but keep material away from crowns and stems.
  • Water thoroughly if season is dry.
  • Cultivate around vines with care as physical injury will cause wilting and death of injured stems.
  • Continue to guide new growth by tying to supports as needed.
  • Lightly prune Group I Clematis immediately after flowering to shape the vines if needed.

Summer:

  • Watch for signs of fungal wilt and remove and destroy affected plant parts if it occurs, then sterilize pruners with bleach solution.
  • Group II Clematis may be pruned back by one-half after main flush of bloom to encourage strong growth and new flowers.
  • Continue to water if conditions indicate.

Fall:

  • Check to be certain that the vines of Group I and II varieties are tied securely to supports to withstand winter wind and snow.
  • Mulch if desired, keeping material away from the crown.
  • If the season is dry, water well and deeply.

‘Sweet Summer Love’ growing amazingly well in my mom’s garden.

‘Betty Corning’ is a charmer. I grow it by the front door where its nodding blue bells soften the railing.

HOW DO YOU PRONOUNCE CLEMATIS?

Well, how have you been saying it in your head while you read this? I am a firm supporter of the CLEM-uh-tis pronunciation, but there are a lot of clem-MAH-tis folks out there as well. Say it however you like, just grow them!

‘Princess Diana’ is on my must-grow list. It looks particularly good growing through dark-leafed shrubs.

OTHER RESOURCES

The Plant Lover’s Guide to Clematis is an excellent reference.

FAVORITES

You know this is like asking a parent who their favorite child is, right? Well, I do have a few favorites, but I’m always discovering new clematis that I love as well.

  • ‘Sapphire Indigo’: A Group 3 non-vining clematis with deep blue (OK, purple-ish) flowers that absolutely cover the plant for most of the summer. Great seedheads as well.
  • ‘Guernsey Cream’: A classic Group 2 that blooms very early and is just so creamy wonderful. I’d never be without it.
  • ‘Princess Diana’: I have two of this Group 3 clematis because I thought the first one had died and I couldn’t be without its tulip-shaped pink bell-shaped flowers. The first one was fine and now there are two.
  • ‘Sweet Summer Love‘: A small-flowering Group 3 with a lovely scent and crazy amounts of flowers.
  • ‘Etoile Violette’: Dark purple, long-lasting medium-sized blooms that combine so well with so many other things and happily climb up my deck railing.

I don’t grow ‘Stand by Me’, a new introduction from Walters Gardens and Proven Winners last year, yet but I have my sights set on a mass planting of it because it comes to me in my dreams. I’m only sort of kidding. (Update: I planted three ‘Stand By Me’ clematis in a clump in the new patio garden area I redid in summer 2019.)

‘Guernsey Cream’ will always be a favorite of mine.

ANY NEGATIVES?

Well, yes, because there are downsides to any plant, particularly one that has such genetic diversity. Clematis wilt can be a problem with Group 2 clematis, although I don’t think I’ve ever experienced it. It’s a disease caused by a root-rotting fungus in which stems just suddenly wilt, often just as they are about to flower. To my knowledge, the only thing you can do for it is cut away the affected stems. Planting deeply helps new stems regrow and allows the plant to develop deep roots that will hopefully prevent clematis wilt from striking and, if it does, help it bounce back.

Some clematis are aggressive and even invasive in some areas. Sweet Autumn (Clematis terniflora) is a massive grower in most areas and will quickly cover anything and everything with a huge vine with thousands of small, white flowers. It is considered an invasive species in some areas, so handle that one with care.

‘Alba Luxurians’ is a delicate white clematis that gets green accents on its petals. I took this photo when it grew in a container but I moved it to grow up a spruce.

Other clematis are rampant self seeders. I presume this is highly dependent on where you garden because I’ve never had a clematis self seed in my garden in 17 years, but take note that some may have that habit in your garden.

Do you grow clematis? If so, I know you have a favorite. Share it in the comments. I might need to add to my collection.

This young late-summer-flowering clematis has not been regularly pruned, so I’m cutting back old growth to the topmost buds. It will be pruned again after flowering in autumn

© Time Inc

Clematis mingle well with existing climbers and wall shrubs, taking up little extra space. They can deliver flowers every month of the year and are largely self-clinging, grabbing on to their supports with twining leaf stalks.

The best times to plant clematis are early autumn and now, in spring, when the soil is still moist but warming up.

April and May belong to Clematis alpina, C. macropetala and their cultivars. Undemanding and very hardy, these dainty clematis with pretty nodding flowers perform well in average soils and any aspect, so long as their roots are shaded from strong winds and sun.

They are soon joined by romping C. montana, another easy-going type with so many blooms you can hardly fit a pin between them. Fragrant pale-pink ‘Mayleen’ is a particularly good choice, and if any of these spring clematis need pruning, ensure you do so immediately after they’ve flowered.

During May and June, large-flowered hybrids such as ‘Nelly Moser’ and ‘Niobe’ open their massive blooms. These are more particular and, if left to their own devices, will pine and dwindle. In late winter, trim stems above their topmost pairs of fat buds and again 
after the first flush of flowers.

© Alamy

‘Niobe’ boasts impressive giant blooms that unfurl in May and JuneAs summer progresses, late flowering, sun-loving Viticella hybrids such as ‘Etoile Violette’ open from June to September. These are pruned hard 
in late winter, back to 12in (30cm) beyond strong buds.

For late summer and autumn, 
C. texensis cultivars with blooms that resemble inverted tulips, begin to join 
in. These tend to die right back during winter and push from just below ground each spring. All these summer flowerers need a high-potash rose fertiliser or similar in springtime, followed by a generous mulch of well-rotted compost and a couple of liquid feeds.

The ‘lemon-peel’ blooms of 
C. orientalis and C. tangutica turn into wispy seed heads, overlapping with the muted but welcome midwinter display from evergreen C. cirrhosa cultivars.

These need lots of sun and a sheltered spot. The New Year is heralded by C. ‘Winter Beauty’ and then vanilla-scented C. armandii – both evergreens in need of a sheltered spot. Ensure any necessary pruning is meted out promptly after flowering.

Top Tip

When tackling overgrown borders containing clematis, find and wrap their bases in easily visible horticultural fleece. Without this, the brown, dead-looking lower stems are all too easy to rip up along with weeds.

Clematis favourites

© Alamy

C.alpina ‘Columbine’
Like other C.alpina varieties, this is good 
at looking after itself. Expect nodding blue flowers on plants reaching 2.5m (8ft). Ensure roots 
are shaded and prune 
after flowering.

© Alamy

‘Comtesse de Bouchard’
A tough, easy, pink clematis, which is happier in shadier positions. Reaches 6-8ft (1.8-2.5m), and blooms from June to September. Prune hard in late winter, or more lightly for earlier flowers.

© Alamy

‘Madame Julia 
Correvon’
A distinctive Viticella 
type with wine-red flowers from June to September 
on plants to 12ft (3.7m). Prune in late winter.

© Alamy

C. x triternata ‘Rubromarginata’
Creates a mass of tiny stars with maroon-edged petals and an almond scent. Tolerates dry shade and grows to 10ft (3m).

Clematis care

© Time Inc

  • Plant into well-conditioned, well-drained soil.
  • Position the plants somewhere they’ll have cool roots but sun further up, though many are shade tolerant.
  • Plant large-flowered summer-blooming clematis so 
their stem bases are buried 2-3in (5-8cm) below soil level (see image above). Plant the rest normally.
  • Prune spindly newly planted clematis to 12in (30cm) above soil level to encourage multiple stems.
  • Water during droughts while establishing.

  • Exposure: Part sun to sun
  • USDA Hardiness Zones: 4 to 9
  • When to plant: Early spring
  • Recommended varieties: Niobe, Montana, Sweet Summer Love
  • Pests and diseases to watch out for: Japanese beetles, clematis wilt

Eddie Phan How to Plant Clematis

Clematis roots and vines are fragile and don’t recover well from rough treatment, so handle the plant gently. If your plant has a tiny trellis in its nursery pot, keep it in place and have someone help you hold it up as you remove the pot; otherwise, the trellis can flop over and damage the plant. Dig a hole double the width of the root ball, placing the plant no deeper than soil level. Add a larger trellis right away so the plant has something to grab and grow up.

How to Care for Clematis

Water as it gets established the first few years, but clematis doesn’t like it too dry or too soggy. Feed once a season in early spring after the ground thaws with a general-purpose fertilizer. As the plant matures, prune to eliminate scraggly stems. But because different varieties bloom at different times, read the label or look up your variety online for proper pruning times. In general, if a plant blooms in early spring, prune it right after that. Summer blooms mean it blooms on new wood, so prune to about 18 inches above ground in very early spring. When in doubt, wait a season and record your observances before snipping.

Can you grow clematis in a pot?

Yes, but choose a large pot and a clematis that can tolerate one zone hardier than where you live so it survives the winter. For example, choose a zone 4 plant if you live in zone 5. Also, plant it by itself in the pot because it doesn’t compete well with other plants.

How long does it take to grow a clematis?

Clematis is perennial so it comes back every year. But be patient! The first year it may appear that there’s not much going on. Your clematis needs at least two to three years to flourish because its complex root system takes time to establish.

Will a clematis climb by itself?

Yes and no. The plant climbs by wrapping its leaf stems around a structure, but it doesn’t like anything that’s more than about ½” in diameter to grab. For example, it cannot climb up a solid mailbox post or light pole. You need to give it a little help by attaching netting, fishing line, or twine to a standard trellis. The more options you give it to grab, the better it climbs.

GROWER TIP: “The classic advice for clematis is that it likes its feet in the shade and head in the sun,” says Stacey Hirvela, horticulturalist for Proven Winners Color Choice Shrubs. “Keep the root zone cooler with mulch, a neighboring plant like a day lily or juniper, or even a rock. Make sure the top of the plant gets at least six hours of sun.”

Arricca SanSone Arricca SanSone writes for CountryLiving.com, WomansDay.com, Family Circle, MarthaStewart.com, Cooking Light, Parents.com, and many others.

Leave a Reply

Your email address will not be published. Required fields are marked *