How to Grow Great Clematis - easily

Clematis are great-looking climbers in any garden and are a deservedly popular and hardy plant. They include early, mid-summer and late-summer flowering varieties and their stems can range in length from anything between 6ft to over 30 ft. At Winsford Walled Garden we use over 120 clematis varieties to cover the walls and provide colour throughout the gardens. On this page we explain how we grow clematis so successfully.

Purchasing and hardening off
The best time to plant clematis is around Easter which gives them the maximum time to get established in their new location. If you do obtain clematis late in the season as I did last year around November, it will pay you to keep them under cover and maintain the pot compost just slightly moist until planting.

Often clematis arrive in especially tall, slim pots, check the pot is moist. If it isn't choose another plant, if your chosen plant is the only one available, pop it out of its pot to check the roots are looking good. They should be yellow with healthy white growing tips. If those tips are all brown the roots have rotted.

When you purchase your new plant always enquire if the plant has 'hardened off'. This is the process used to acclimatize a plant which has been under cover and get it used to being outside. You  need to avoid buying a plant which has recently arrived at the seller's site after being cocooned inside the grower's nursery and planting it straight in your garden.  Normally it  takes about two to three weeks of progressive treatment of putting the plant outdoors during the day and returning it under cover each evening. On particularly bitter days it is best to keep the plant under cover. The important thing during hardening off is to ensure plenty of fresh air around your plant(s).

Planting your clematis for best results
Planting is key to successfully growing clematis. Clematis grow best when their roots are located at least eighteen inches (45cms) away from their support - be it a wall, pergola or shrub. In common with many climbers clematis prefer to have cool roots and warm, sunny foliage, so always locate your clematis on the cooler shady side of any post or plant.

At Winsford we have a number of the larger montana group of clematis (up to 30ft) and these are rooted up to one metre from the base of the south-facing wall which can attain over 140 degrees in summer. Because the wall faces south, planting the clematis was postponed until sufficient shrubbery was established beneath the wall which could shade the clematis root system.

Measure the pot height against your spade depth and dig accordingly. The hole needs to be about twice the width of the pot and about 1.5 times its depth. A sprinkle of bone meal at the bottom of the hole is always a good idea. Be sure to plant your new clematis with about two inches of soil on top of the original pot soil. This helps to encourage new shoots which should be your main aim during the first year or two. By encouraging new shoots then, in the event of losing one, you will not necessarily lose the whole plant. Safety in numbers.

The most common mistake when growing clematis
The most common problem with clematis is the result of gardeners being too fixated upon achieving maximum foliage growth during that first summer. Big mistake.

Any new clematis will put on its maimum foliage growth at the expense of the all-important rootstock. Then, when new owners admire the six to eight feet of growth in the autumn they are naturally expectant of even greater results during the second year. So it is an even bigger shock for the gardener when the plant doesn't make to the next summer.

The reason for this is that the poor immature rootstock tried to keep the whole of the plant alive and simply exhausted itself. The gardener needs to help young clematis by cutting them back to about a foot high at the end of the first year. No matter how much your plant may have grown, it's best to 'bite the bullet' and cut your plant back. In this way the rootstock should not have to struggle too hard during the winter.

Then, at the end of the second summer simply prune your clematis according to its group.

Clematis Groups and pruning
There are three distinctive clematis pruning groups.

Group One - Light Prune after flowering
Following the initial first year's hard prune members of this group need only receive an annual trim and tidy-up after flowering. Group members include clematis amandii, C. alpina, C. macropetala and the large montanas.

Group Two - The larger flowered hybrids
Group members include the larger flowered hybrids which flower on the previous season's growth and sometimes flower a second time in late summer on new growth. Pruning should be completed around February (late winter).

Group Three - Hard Pruned late flowering clematis.
This group flowers on the current season's growth because of this, there is no need to retain the old stems. Around late February group members need their stems pruned back to about 2-3 feet. Never mind that you will undoubtedly remove some good stems and buds. Over time the stem will extend itself with maturity.

Examples of Clematis groups.

Group One	Group Two	Group Three
amandii	Alanah	aromatica
Broughton Star	Barbara Dibley	Barbara Harrington
Cartmanii Joe	Dawn	Earnest Markham
cirrhosa	Fireworks	Hagley Hybrid
Freckles	Lemon Chiffon	Hendersonii
Freda	Marie Baselot	Jackmanii
macropetala	Mrs Cholmondley	Perle d'Azur
Montanas	Wada's Primrose	viticella

For more clematis photographs taken at Winsford Walled Garden