Fabulous flowers: top tips for growing compact clematis
PUBLISHED: 10:00 23 April 2017
Clematis are one of the most popular varieties of garden flower, so how can you get the best from your blooms?
He’s spent more than five decades searching for, breeding and developing some of the world’s best clematis. Expert grower and genial gentleman Raymond Evison, who has championed compact and highly rewarding cultivars suitable for containers and smaller spaces, is now looking for maximum impact with his latest Chelsea showstopper.
The framework is already in place on his impressive clematis nursery on the Channel Island of Guernsey. It’s a contemporary seashore scene featuring undulating metal frames which will be adorned with ‘waves’ of white and blue clematis, featuring a montage of more colourful varieties of ‘flotsam and jetsam’ below. More than 2,000 plants are being grown for the exhibit.
It’s likely you will have passed some of Evison’s famously compact clematis in your quality local garden centre. Indeed, his nursery produces more than two million of these beautiful climbing plants a year which are exported all over the world - China and Japan are currently particularly fond of his world-famous blooms, but you can grow them just as easily at home.
Over the years, his business - like him - has gone through peaks and troughs. Suffering in the recession, four years ago Evison sold his farm and home to plough money into the business to keep it afloat, and has fought his own personal battles with bowel and prostate cancer. Anyone else might have thrown in the towel, but not Evison. And now business is on the up again. “I never considered giving up,” he reflects. “We now have new markets in China, a trial order has gone to South Korea and the US is growing.”
Some 85% of his clematis are the new, more compact varieties, ideal for those with small spaces or who want to grow really floriferous plants in pots. “The process started in 1994-5. We could see that people would have smaller gardens and less time for gardening and so we thought it was important to breed and develop more compact clematis that would flower for longer and give better value for money.”
The ones grown specifically for containers are compact, with more branches and more flowers per stem. You will see flowers near the base of the plant as well as at the top of it. “If you look at some of the old clematis varieties, they will have a solitary single flower on the end of a stem. Our clematis flower up and down the stems.”
While historically timing and method of pruning has depended on the type of clematis you grow - Type 1, 2 or 3 - the compact ones are less complicated. Most need pruning in late winter or early spring, cutting all stems back to 15-22cm (6-9in) above soil level.
Three new Evison varieties are being launched at Chelsea this year - Sacha, a mid-deep blue, a double red called Charmaine and a white type called Kitty, named after a young leukaemia sufferer, the niece of a friend of Evison, launched in conjunction with the Anthony Nolan Trust.
So, how can you achieve success with compact clematis? Evison advises:
Don’t use a plastic pot. It will heat up too much during the summer and won’t give the clematis any root protection.
The container should be a minimum of 45cm (18in) deep and the same diameter. A plant in that pot size should be OK for around five years before transplanting it to a larger pot.
Good drainage is important. Use John Innes No 3 mixed 50:50 with a multipurpose compost.
Clematis don’t like their roots in the sun so if you are growing clematis in a container, surround it with summer bedding plants in the top of the pot to give added interest and colour and create its own microclimate. Remove the top 3in (10cm) of compost, replacing it with fresh, when you take out the bedding plants at the end of summer.
Plant new plants deep - an extra 6cm (2-3in) deeper than the pot that it came in. They are climbing perennials and need to build up roots down below. Planting more deeply can help prevent large-flowered varieties from succumbing to clematis wilt.
If the plant gets clematis wilt, cut it down and, if you have planted it deeply, there’s a good chance it will grow back.
Plant the strong-coloured clematis in the sun and paler shades in the shade. Those which grow in a shaded area only need three to four hours of good strong sunlight per day.
For the best results, grow clematis through other plant material such as roses, ceanothus, pyracantha. If you want to grow it up a wall, grow it through other plant material.