Clematis In Containers–Take Two

Update:  Many technical difficulties in the original post, so I am trying to post this again.  Thanks for your patience!

I wanted to share with you an article I wrote for a local small newspaper (no longer in business) when I was their garden writer.  My focus for this column was “Container Gardening,” and I came up with this topic one week.  All of the pictures were taken by me of clematis that I grow in my garden.  Enjoy!

Clematis ‘Louise Rowe’

Clematis is a diverse genus of flowering vines. While there are some monsters that will grow twenty to thirty feet of stems in one season, others will remain at a petite eight to ten feet tall and are suited for container gardening.

My favorite clematis expert is Portlander Linda Beutler, whose book Gardening with Clematis: Design and Cultivation is filled with terrific tips and tricks especially suited to Northwest gardeners for getting clematis to perform at their best. After reading her book and hearing her speak at gardening workshops at the Camas Public Library and Joy Creek Nursery, I decided to give container-grown clematis a try for myself.

To begin this gardening adventure, I started discovering plants that will thrive within the constraints of a container. I’ve had good luck so far with three large-flowered hybrids. The first is “Asao,” which has darkish pink blooms accented with lighter pink centers and which blooms early in the season, from the end of April until the end of May. Linda advises that if you sparingly prune off the dead ends and fertilize it at half strength right after it finishes its first bloom, it will often rebloom for the month of September. This clematis doesn’t need any hard pruning to keep it in full fig, just a light trim to keep it neat. ‘Asao ‘ is quite happy in my garden growning in an eighteen-inch tall and wide turquoise-blue plastic pot along with the October through February-blooming double soft pink Camellia sasanqua ‘Jean May.’ ‘Jean’ stays much smaller than her later blooming, sometimes tree-sized, Camellia japonica cousins. Because this evergreen camellia is more shallow-rooted than the clematis, it is happy to spread its roots near the upper portion of the pot while the clematis burrows its roots deeper down in the pot, thereby cooperating in limited quarters. I also like to add some shallow-rooted annuals, including summer-blooming pastel sweet peas and baby-blue ‘Cambridge Blue’ lobelia with a dark purple, fragrant heliotrope to the mix to create a container that has something of interest going on four seasons of the year. This pot thrives in a covered entryway to the house so that harsh winter rains don’t crush and dissolve the somewhat tender camillia blossoms.

Clematis ‘Asao’

Two other of my favorite clematis for containers include the double purple ‘Daniel Deronda,’ and the double pale lavender ‘Louise Rowe.’ Both ‘Daniel’ and ‘Louise’ flourish under the same regime of pruning and fertilizing that I use with ‘Asao,’ and both bloom at about the same time as ‘Asao.,’ ‘Daniel’ is wonderful growing up through something yellow or chartreuse. I placed the container so it grew near a large yellow David Austin English rose ‘Graham Thomas,’ with some airy, five-foot tall Verbena bonariensis rising up on pencil-thick stems as a purple haze. In a container setting, you might select a diminutive chartreuse-foliaged shrub in a neighboring pot, such as the small, two-foot tall and wide evergreen Hebe ‘Co-ed,’ with chartreuse foliage maturing to green, and purple summer flowers. (Update July 2010:  I would no longer recommend Hebe shrubs in general, because our recent cold winters have killed every one of mine.  A better option for a small evergreen would be a heather or heath, which also blooms in the winter and has lovely and often colored evergreen foliage in other seasons.)  Another colorful choice would be the two-to-three feet tall Berberis thunbergii “Aurea Nana,’ with golden foliage, mid-spring yellow blooms and red berries in the fall.

‘Louise’ is a fascinating clematis to watch over the growing season, because it can simultaneously have single, semi-double, and double flowers in bloom. Her flower color is set off by close proximity to the color blue, perhaps used as the color of the container in which she grows, which is what I did, or accomplished by growing other blue-flowered or -foliaged plants close at hand. One that I like is Cerinthe major ‘Purpurascens.’ An annual that reseeds rather freely in my garden, it has blue-green leaves on arcing stems, and at the tips of each stem flowers a small tubular dark purple blossom. It looks great combined with that stalwart and infinitely blendable annual, lacy Dusty Miller. Both annuals keep their good looks from spring through fall, helping not only to intensify the clematis flower color but also to carry the container over while the clematis is in-between first bloom and rebloom.

Clematis ‘Daniel Deronda’

True to their vine nature, pot-grown clematis need some kind of structure upon which to grow. I met this need by placing my containers near structures upon which the plant could grow, such as a large rose and a handrail and spindles. If you wanted a freestanding container, you could use a narrow piece of trellis at least twice the heigth of the pot and eight to ten inches below the soil surface to anchor the structure. Trellis can be purchased, or homemade out of wood, copper tubing, even painted one-half inch PVC pipe connected with appropriate fittings. Clematis will need to be tied to any supporting surface diameter greater than one-half inch. You can wrap larger supporting posts with chicken wire and the clematis should be able to climb up the structure on its own, with just a little help from you in the form of attaching it with twine while the plant is young.

Because these vines will be living in pots for several years, it’s a good idea to choose high-quality potting soil. I succeeded with my three clematis by following many of Linda’s tips on the best type of potting soil and planting method. She recommends looking on the label of the soil to see if it contains something to lighten the soil like sand or pumice, composted manure and worm castings, kelp meal, dolomite lime, bat guano and bone meal. If you make your own homemade compost, add some of that to the mix as well. Before filling your pot with soil, put some fine metal mesh in the very bottom of the pot to cover the drainage holes so the soil doesn’t run out, next a couple of inches of gravel for good drainage, then add soil mixed with a sprinkle of slow-release fertilizer about halfway to the top, after which you can place your new plant into the pot. You want to cover the root ball plus about three inches of the stems. Adjust the soil level so the plant is at the appropriate depth, insert whatever supporting device you chose to use, then fill in the container with more of the potting soil until you’re within a couple of inches of the top of the pot. Water at this point, allow the soil to settle, and add soil as necessary so the soil level remains at a couple of inches below the top of the pot. Tie the clematis to the structure, then finish with a thin top layer of gravel for a mulch. For maintence, it’s best to water every one to three days depending on how dry it is. Linda also recommends that six weeks after you pot up the clematis you should start using flower-boosting fertilizer about once a week until the plant has set bud, then stop fertilizing until after it has finished blooming and you’re preparing it for fall rebloom.

If you’re like me, you will quickly become enamored of these amazing vines, and you will be well on your way to enjoying dapper spring and fall-blooming clematis that may well be the abundant showpiece of your container garden.

Photos and content copyright 2007-2010 Minerva’s Garden

It’s Tuesday, so please head on over to the Tuesday Garden Party, where you will see lots of beautiful gardens!  And enjoy this hot weather!

 


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14 Comments

  1. Jenny said,

    July 6, 2010 at 5:40 pm

    I can’t see to grow clematis to save my life. Love them, but just can’t get them to grown. Yours are beautiful!

    • minervasgardenwriter said,

      July 6, 2010 at 6:08 pm

      Thanks! They can be kind of fussy about light conditions–I’ve killed my fair share by planting them someplace they did not want to be. And I have moved several of them around the garden until I found a spot that they liked. But, to me, the flowers are so pretty that they are worth the trouble to grow. A lot depends on the specific variety of clematis you want to grow–some like full sun, while others need morning sun and afternoon shade. I have had good luck with a couple that have been very easy to grow in the ground, at least for me. They like to be in full sun, if that helps. They include ‘Jackmanii,’ which is a lovely purple one that gets pretty big, and ‘Romantika,’ a very dark purple one with yellow center that you can cut back after the first bloom and it will usually rebloom. Also, I am in Gardening Zone 8. They are harder to grow in colder gardening zones–the coldest one I could grow them in was Zone 5, and only certain ones and only with protecting them in the winter.

      Maybe you could trying growing them in large containers, because then you can control the soil more easily and can place them in a sunny location possibly. Hope this helps a bit!

  2. Ott, A said,

    July 6, 2010 at 6:09 pm

    Thanks for stoppin’ by for a Latte’. Your clematis look beautiful, such pretty colors. Happy Gardening!

    • minervasgardenwriter said,

      July 6, 2010 at 6:11 pm

      Thanks, Ott, A–I enjoy your blog!

  3. July 6, 2010 at 7:35 pm

    […] This post was mentioned on Twitter by Gardening Guru. Gardening Guru said: Clematis In Containers–Take Two http://bit.ly/bTd7lh […]

  4. Melinda said,

    July 6, 2010 at 8:08 pm

    I was successful with clematis only once – and then we moved. I’m still trying to get one started on the farm – first drought, then the deer. Maybe it’s time to try again – they are so beautiful!

    • minervasgardenwriter said,

      July 6, 2010 at 8:16 pm

      I wish you good luck with them–I think they’re pretty too. And thank you for leaving a comment–it is appreciated!

  5. iMadeItSo said,

    July 6, 2010 at 9:25 pm

    i’m glad you wrote all this, and i’ll be coming back to reference it… i bought a small clematis, but it is still sitting in its tiny pot. i haven’t found the right place for it, but now i’m thinking maybe a container is the way to go. maybe! thanks for the info.

    • minervasgardenwriter said,

      July 6, 2010 at 9:44 pm

      So glad it was helpful–thanks!

  6. zentMRS said,

    July 6, 2010 at 9:40 pm

    Oh my goodness – those are gorgeous!! Thanks so much for sharing them!

    • minervasgardenwriter said,

      July 6, 2010 at 9:44 pm

      Happy to oblige. Thanks for leaving a comment!

  7. July 7, 2010 at 6:56 pm

    Wow- your clematis are much nicer-looking than mine. 🙂 I continue to grow them, though because I love the flowers. I’m going to take some of your recommendations you mentioned in the first comment. Thanks for sharing this at the TGP!

    • minervasgardenwriter said,

      July 7, 2010 at 7:07 pm

      Great–I’m glad it was helpful! And I am so enjoying your series this week–thanks so much for posting these, and hosting the Tuesday Garden Party.

  8. Lisa H. Zuar said,

    September 11, 2011 at 1:44 pm

    HI,
    I’m not sure whether you still check for comments but I LOVED your pictures and advice. I, too, loved the book by Linda Beutler. I have had great success with clematis in the ground (zone 5) but only mixed results with clematis in containers. Would you be willing to tell me which particular potting mix you used? I don’t think I’ve hit upon the best choice yet and I think it makes a BIG difference. Thank you for sharing your article and pictures. I enjoyed them more than I can say. Thank you. Lisa


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