Clematis are popular climbing plants, providing height and colour throughout the season. They look particularly good with roses. There’s a huge variety of clematis to grow, with flowers ranging in size from small bells to large dinner plates.
Clematis can be good for wildlife, clothing walls, fences and trellis with leaves and flowers, which provide shelter for insects and sometimes birds. Some clematis flowers are visited by pollinators, while the fluffy seedheads of Clematis tangutica cultivars may be used as a nesting material by house sparrows.
How to grow clematis
Most clematis require a fertile, moisture-retentive soil and full sun, but there are some that tolerate shade. They’re hungry feeders, so add plenty of organic material when planting and feed weekly with a high potasth fertiliser in summer. All clematis have roughly the same planting needs, but need pruning according to their pruning group (see below).
More on growing clematis:
Find detailed planting and growing advice for clematis, below.
Where to plant clematis
All clematis do best when their roots are in shade and top growth in the sun. As a rule, most clematis do best in garden soil rather than in containers. If growing in a pot, plant in John Innes no.3 with added grit.
Clematis are suited to a range of planting locations. Less vigorous types are suitable for growing up a trellis, while rampant climbers such as Clematis montana can be planted at the base of a large wall or shed, and trained to cover it. Other types are perfect for scrambling through trees, and you can even grow clematis as ground cover.
Here, Monty Don demonstrates two methods of growing clematis in a flower border, as opposed to a garden wall. First, he shows how to plant late-flowering Clematis viticella ‘Abundance’ under a wigwam of hazel bean sticks. Then, he recommends growing clematis through shrubs – here planting Clematis x durandii through Rosa complicata. Clematis require a cool, free root run, so watch now to discover how to create the right size of planting hole, together with tips on planting depth, which type of organic matter to add to the soil, plus volume and frequency of watering.
How to plant clematis
Plant clematis in spring or autumn. Clematis are hungry feeders so dig a hole twice the width and depth of the root ball and part fill it with some well-rotted organic matter and a sprinkling of bone meal or other fertiliser. Clematis benefit from being planted around 5cm deeper than they were in their original pot, as this can prevent the fungal infection clematis wilt. Remove the plant from its pot and place the root ball in the hole, checking the planting depth, and backfill with soil. Firm in well and water thoroughly. Continue to water the clematis every week or so until it starts to show healthy signs of growth.
In this video, Monty Don shows you how to plant Clematis alpina, so it will climb up into a tree and provide cascades of spring flowers for years to come. He offers tips on how to prepare the planting hole, how deep to plant it, and how to help it settle in:
How to care for clematis
Clematis are hungry, thirsty plants. Water regularly in dry weather and feed with a high potash fertiliser, such as a tomato feed, just before they start to bloom. This is particularly important when growing clematis in pots. The feed should encourage a healthy crop of flowers.
In our Golden Rules video, Marcel Floyd of Floyds Climbers and Clematis gives his top tips on caring for clematis, including why it’s important to prune them right after buying. He also reveals when to water and how best to feed them:
How to prune clematis
Clematis are divided into three pruning groups, as follows:
Group 1 clematis flower on wood created the previous year. They therefore don’t require any pruning at all.
Group 2 clematis also flower on the previous year’s growth and should be lightly pruned in February. Simply remove damaged or weak stems to make way for fresh growth. Then trim other stems to just above the strongest and highest pair of buds. If cut back too hard, you’ll lose a year of flowers.
Group 3 clematis flower on the current season’s growth. Prune plants hard in early spring, before growth begins. Cut back plants to just above a healthy bud about 30cm from the soil. If you don’t prune Group 3 clematis, you’ll end up with a tangled mass of stems with flower growing only at the very top of the plant.
In this video clip from Gardeners’ World, Monty Don explains how to prune a summer-flowering (Group 3) clematis:
How to propagate clematis
The best way to propagate clematis is by taking softwood cuttings in April or May. Remove a section of stem from the current season’s growth, which is ripe but not too woody or too soft. Fill a garden pot with cutting compost and water. Add a fine layer of grit to the top of the compost.
Cut a section of the stem above a leaf joint. Your cuttings should be about 7cm long. Remove some of the leaves so each cutting is left with just one. Push the end of the cutting into the pot so it supports itself.
Cover the pot with a clear plastic bag or place in a propagator and leave in a warm place but out of direct sunlight. Cuttings can take up to five weeks to root.
In this video, Monty Don guides you through the process of taking clematis cuttings. Using the variety ‘William Kennet’, he shows you which stems to select, how to trim them ready for planting, how deep to insert them, and how to provide the conditions they need to root successfully:
Clematis can also be propagated by layering, simply take a low-growing stem and peg it to the ground with a tent peg or similar. You can propagate clematis from seed but the offspring of the large-flowered hybrids will vary from the parent plant.
Growing clematis: problem solving
Clematis wilt can cause huge problems for clematis, growers, causing clematis to die suddenly without apparent reason. Larger flowered types are the most likely to be affected. It’s easy to spot as plants quickly wilt. Clematis wilt is a fungal disease. Prune out all affected stems and burn them.
Clematis are also prone to an attack from earwigs, which chew holes in the flower petals. This damage is only cosmetic and doesn’t harm the plant. If you’re really concerned you can create earwig traps by pushing a 1m long cane into the ground next to the clematis. Stuff a plastic plant pot with straw and place it upturned on the top of the cane. Earwigs will use this as shelter during the day, giving you the opportunity to catch and rehome them.
Clematis varieties to grow
- Clematis ‘Vyvyan Pennell’ (pictured above) – impressive giant, double, pale purple blooms in May, June and September. Height 3m
- Clematis ‘The President’ – deep purple, large flowers. This plant has been grown in gardens for over a century. Height 3m
- Clematis macropetala ‘Markhams Pink’ – double drooping pale-pink flowers in April and May. Height of 2.5m
- Clematis montana ‘Freda’ – single flowers of four petals, white and pale pink in May and June. Reaches a height of 6m
- Clematis viticella ‘Confetti’ – delicate pink flowers in July and September. Reaches a height of 2mClematis ‘Pearl d’Azure’ – a popular old variety with sky blue flowers in July to September. Height 3m
- Clematis tangutica ‘Bill MacKenzie’ – small, bell-shaped yellow flowers in late summer followed by stunning fluffy seedheads. Height 4m
- Clematis ‘Ville de Lyon’ – two toned light and dark pink flowers from June to September. Height 3.5m
- Clematis ‘Gypsy Queen’ – large bright blue/purple flowers from August to October. Height 3m