Climber
How to grow clematis
Clematis species and hybrids
Plant clematis in March to May or September to October, in deep, moist, fertile soil with the top growth in sun and the roots shaded. Set large-flowered hybrids 5 to 8 cm deeper than they were in the pot, so they can reshoot from below ground if wilt strikes; plant other types level with the soil. After that, success depends on knowing which of the three pruning groups your plant belongs to, and on watering through its first two summers.
- Hardiness
- Fully hardy (most)
- Position
- Flowers in sun, roots in shade
- Soil
- Deep, rich, moisture-retentive, free-draining
- Ideal pH
- 6.5 to 7.5
- Water
- High, a bucket a week in dry weather for the first two years
- Feeding
- Moderate feeder
Sowing and planting clematis
WhenPlant Mar to May or Sep to Oct, large-flowered hybrids 5 to 8 cm deeper than the pot; flowers by group from Mar to Oct
Starting off
Plant pot-grown clematis Mar to May or Sep to Oct, large-flowered hybrids deep, with a stone or low plant to shade the roots. Propagate by internodal softwood cuttings 5 cm long in May to Jun at 18 to 21 °C, rooting in 6 to 8 weeks, or by layering a low stem in Mar, severing a year later. Species seed sown fresh in autumn germinates in spring; hybrids do not come true.
Spacing and planting
Plant 1.5 to 2 m apart along a fence, or one per obelisk; dig a hole 45 cm deep and wide, setting the root ball of large-flowered hybrids 5 to 8 cm deeper than it was in the pot so buried buds survive wilt, and other types level with the soil. Compact 'Boulevard' types are fine in a 45 cm pot of loam-based compost; large-flowered hybrids need 60 cm.
Varieties worth growing
- C. alpina 'Frances Rivis'
- Group 1. Nodding blue lanterns in April, then silky seed heads. Compact at 2 to 3 m and tough enough for a cold, exposed or north-facing wall.
- C. montana 'Elizabeth'
- Group 1. Pale pink, vanilla-scented flowers in May on a plant that will cover 8 m or more. For a large wall, shed or tree, not a small fence.
- 'Nelly Moser'
- Group 2. Large pale pink flowers with a darker bar in May and June and again in late summer. Keeps its colour best on a north or east wall, out of strong sun.
- 'Étoile Violette'
- Group 3 viticella type. Masses of deep purple flowers from July to September, simple to prune and very seldom troubled by wilt. The safest first clematis.
- C. cirrhosa 'Freckles'
- Group 1, evergreen. Cream bells speckled maroon from November to February. Needs a warm, sheltered wall, since it is less hardy than the others.
Clematis month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Nothing to do. C. cirrhosa is in flower.
- February
Prune group 3 to 30 cm above a pair of buds, and group 2 lightly to the first strong pair. Cut every newly planted clematis to 30 cm.
- March
Finish pruning early in the month. Feed and mulch 5 cm deep, keeping it off the stems. Plant. Layer a low stem.
- April
Plant. Tie in new shoots before they tangle. Start the fortnightly liquid feed. Check for slugs.
- May
Tie in every fortnight. C. montana flowers. Take internodal cuttings.
- June
Tidy group 1 plants straight after flowering if they have outgrown their space. Stop the liquid feed as each plant starts to flower.
- July
After the first flush on group 2, cut some stems back to a strong bud to encourage a second. Water with a bucket a week.
- August
Group 3 at its peak. Keep watering young plants. Watch for mildew.
- September
Plant while the soil is warm.
- October
Plant. Leave the seed heads for winter interest.
- November
Nothing to do.
- December
Nothing to do.
Feeding clematis
A fairly hungry climber that responds to potash and a cool, mulched root. Feed in early spring, liquid feed until the flowers open, then stop: feeding in flower shortens the display.
Fairly hungry, a potassium-leaning feed (rose/tomato type) from spring to flowering; mulch and keep the roots cool and moist.
Feeding plan
At planting
5 g per litre of root ball, dusted directly onto the roots: 10 g for a 2 litre pot, 15 g for a 3 litre pot. Once only.
Late February to March, each year
Potassium Rich Fertiliser 11% K
100 g/m², the middle of the label range for beds. The root area of one clematis is about half a square metre, so 50 g per plant, scattered and lightly forked in.
March, after feeding
Garden compost
A 5 cm mulch over the root area, kept a hand's width clear of the stems.
April until the first flowers open, every 2 weeks
3 to 6 ml per litre of water: 27 to 54 ml in a 9 litre can, one can per plant. Stop when flowering starts.
Pots, April until the first flowers open
3 ml per litre of water once a week in place of a plain watering. Resume after flowering until the end of August for group 2 plants that repeat.
Signs to watch
Few, small flowers and lush leaves
Nitrogen excess or wrong-group pruning
High-potash feed and check the group
Leaves yellow between the veins in summer
Magnesium short
Epsom salts
Pale leaves and dry edges in a pot
Dry roots
A bucket a week and a 5 cm mulch
Pests, diseases and problems
A healthy plant suddenly collapses, often just as the buds open; stems and leaf stalks turn black
Clematis wilt, a fungal disease mainly of large-flowered early hybrids
Cut every affected stem back to healthy tissue, below soil level if need be, and bin the prunings. Deep-planted clematis usually reshoot from buried buds. Viticella and species types are rarely affected.
New shoots eaten off at the base in spring; bark stripped from the lower stems
Slugs and snails, a common reason for a plant that seems to fail to come up
Check after dark in March and April and pick off; keep the stone or tile that shades the roots from becoming a slug shelter by lifting it weekly.
Ragged holes in petals in summer
Earwigs feeding at night
Trap in an upturned pot of straw on a cane and move them elsewhere. Light damage is best ignored.
White powdery coating on leaves and flower buds in late summer
Powdery mildew, most often on late-flowering types that are dry at the root
Water with a full can weekly, mulch, and thin congested stems at the next prune so air can move through.
Early flowers on a large-flowered clematis open green or with green streaks
Low temperatures while the buds formed, not a disease
Nothing needed. Later flowers come true once the weather warms.
Foul-smelling white or pink ooze from a stem near the base in spring, growth above wilting
Slime flux, bacteria entering a stem split by frost or damage
Cut the stem out below the ooze into sound wood. The plant normally regrows from lower down.
Pruning
Pruning and care
Group 1 (C. montana, C. alpina): tidy only, straight after flowering in May to Jun. Group 2 (large early hybrids): light prune to a strong bud pair in Feb. Group 3 (viticella, 'Jackmanii', late types): cut all stems to 30 cm above a bud pair in Feb to Mar. Cut every new plant to 30 cm its first Feb, tie in fortnightly in May to Jun and mulch 5 cm in Mar.
Good to knowKnow your pruning group (1/2/3) before cutting; shade the roots with slates or low planting.
Growing clematis in pots
Choose a compact variety bred for pots, or a group 3 viticella, and give it a container at least 45 cm wide and deep; large-flowered hybrids need 60 cm. Use loam-based compost, plant large-flowered types 5 to 8 cm deep as in the ground, and add an obelisk at planting. Stand the pot where its sides are shaded, or plant low annuals around the edge, because hot roots are the main cause of failure. Water every day or two in summer, scrape off and replace the top 5 cm of compost each March, and repot every three to four years.
Clematis: common questions
How do I know which pruning group my clematis is in?
Go by when it flowers. If it flowers before the end of May on last year's stems it is group 1 and needs only a tidy after flowering. Large flowers in May and June, often with a second flush, mean group 2: prune lightly in February. Anything that starts flowering from late June or July on the current year's growth is group 3: cut to 30 cm in February or March.
Why should clematis be planted deep?
Deep planting buries the lowest buds, which lets the plant reshoot from below ground if the top is killed by clematis wilt or damage. Set the top of the root ball 5 to 8 cm below the soil surface, which also encourages more stems from the base. This applies to the large-flowered hybrids; viticella, species, evergreen and herbaceous clematis are planted with the root ball just below the surface.
Can clematis grow on a north-facing wall?
Yes, several do well there. C. alpina and C. macropetala types, C. montana, and pale group 2 hybrids such as 'Nelly Moser' all flower on a north or east wall, and pale flowers hold their colour better out of the sun. Late red and purple types and evergreen C. cirrhosa need a sunnier, warmer wall.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.