World famous clematis grower and breeder Ray Evison is well-known for his ground breaking varieties of this wonderful group of plants. Compact clematis with amazing flowers that suit smaller gardens and containers.
His previous blog on growing Clematis in containers sparked a lot of interest with MyGardenSchool followers so I was delighted when he agreed to share his advice about growing his wonderful clematis varieties in hanging baskets.
His display of them at RHS Chelsea Flower Show this year was stunning and attracted so much attention. What could be a more wonderful subject for a hanging planted than a glorious large-flowered clematis?
Raymond: Keen clematis gardeners have been trying tried to grow clematis in hanging planters for years, some with success, some not so successful.
The main reason for this has been the choice of varieties and the habit of the clematis. Many of the clematis selected did not have the correct habit; although they were compact they had the wrong flowering habit.
Thanks to some recent new breeding work, at last we have three clematis with the correct habit. What we needed was a clematis variety that flowered low to the growing medium in the basket, within 6-9 ins, 15-22cm of the surface.
Then it needs to put on extra extension growth that will hang down from the container and produce lots of flowers. Clematis Chelsea, Clematis Edda and Clematis Picardy do just that and produce an abundance of flowers for a good number of weeks.
Although the clematis flower very well by themselves, I personally prefer to grow them with a range of summer flowering annuals. These additional plants give added interest, additional colour, and help to keep the root system of the clematis cooler. Clematis just love to grow in a microclimate with other plants.
Each year the colour scheme can be changed. I always like to use grey foliage seasonal plants and white flowering annuals. The grey and white blends perfectly with the colours of these three clematis. Actually any plants with pastel shaded flowers would work very well.
Clematis Chelsea has very pale blue flowers that are produced in great abundance. The flowers are only about 3" (7cm) in diameter and have yellow centres. It is the most compact variety with hanging stems to about 2ft (60cm)
Clematis Edda has deep purple-blue flowers with red centres and are again only 3" (7 cm) in diameter. Edda is a little more trailing than Chelsea
Clematis Picardy has purple-red flowers with red centres, about 4"(8cm) in diameter. This has the longest trailing stems, hanging to about 3ft (90cm)
How to grow clematis in hanging baskets
It is best to use a loam based growing medium (UK: John Innes compost number 3) this gives additional feed and is more sustainable than peat based composts. It does not dry out as quickly
Additional feeds, such as tomato feed or rose fertiliser can be used to keep the plants fresh and healthy
The baskets or hanging planters are best placed in a shady location, rather than full sun
When the clematis have completed their first flush of flowers by mid-summer they can be cut back all the way to just about 4-5 "( 8-10 cm) above soil level in the container. They will regrow and flower freely again in about 6-7 weeks giving a great crop of late flowers.
It is most important to keep the plants well-watered throughout the growing season
Once the plants have finished their last flush of flowers for the season, remove the seasonal additional plants and store the clematis in its container in a cold glasshouse or out building over winter. Do not let the container dry out, so keep the growing medium damp
Just before the clematis starts into growth in early spring, remove the surface of the growing medium, that can easily be removed from the clematis root system, and replace this with fresh loam-based potting mix.
The container can then be placed in its normal outdoor location once the additional seasonal plants have been added. Your clematis will grow and give you many weeks of pleasure.
After several years the clematis root system will have grown too large for the container. So it can be planted out in a garden location and it will grace your garden for many years to come
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