How to Plant Clematis

Clematis is one of the most popular climbing plants, valued for its vibrant flowers and ability to cover fences, walls and pergolas. Planting clematis well sets the foundation for years of growth and flowering. It’s important to give it the right start with careful attention to depth, soil condition and position. Once established, clematis is a strong, vigorous grower that will reward you with stunning seasonal colour.

How to Grow Clematis

Clematis is a hardy perennial that climbs by twining its leaf stems around supports. Different varieties bloom at different times, with some flowering in spring, others in summer or early autumn. With the right variety and care, you can have clematis in flower from May through to September. It prefers full sun on its foliage, but the roots should be kept cool and shaded. A good rule is “head in the sun, feet in the shade.”

Before You Get Started

Choosing the right site is key. Clematis prefers a sunny or partially shaded position with shelter from strong winds. Avoid planting in waterlogged soil or exposed corners. You should also check the flowering group of your clematis—this affects how and when it should be pruned. Group 1 varieties flower early, Group 2 bloom mid-season, and Group 3 flower later in summer. Knowing this from the beginning will make ongoing care much easier.

Planting

Clematis is best planted in spring or early autumn when the soil is workable and not too cold. Prepare a deep planting hole and mix in compost or well-rotted manure to improve soil structure and drainage. Clematis should be planted deeper than most plants—the top of the root ball should sit around 5 to 10 cm below the soil surface. This encourages multiple shoots and helps protect against wilt. Water well after planting and add a mulch around the base to keep the roots cool.

Ongoing Care

Water regularly during the first season, especially during dry spells. After that, clematis is relatively low-maintenance, though it still benefits from feeding in spring with a balanced fertiliser. Adding mulch each spring helps retain moisture and improve soil health. Keep an eye on growth and guide new stems towards supports. Tying in loose growth early avoids tangles and makes the plant easier to manage later.

Pruning and Training

Pruning needs vary depending on the variety. Some clematis bloom on old wood and should be pruned lightly after flowering. Others flower on new growth and benefit from a harder cut in early spring. Understanding your clematis group will tell you when and how to prune. Training clematis involves tying shoots to trellises, wires or fences. They won’t cling by themselves, so regular tying is necessary. Training also helps the plant grow in a balanced shape and prevents bare stems at the base.

Propagating

Clematis can be propagated by layering, cuttings or division. Layering is the easiest method and works well with established plants. Simply bend a low-growing stem to the ground, pin it in place and cover it with soil. It should root over the course of a season, after which it can be separated and replanted. Cuttings taken in spring or early summer can also root in moist compost with a little bottom heat and patience.

Problems

Clematis is generally reliable, but a few issues can affect its health. The most serious is clematis wilt, which causes sudden collapse of stems and foliage. Planting deeply helps prevent this by encouraging the plant to regrow from below ground. Aphids, slugs and snails can damage young shoots, especially in spring. Powdery mildew and other fungal problems can develop in warm, humid conditions. Good airflow, proper watering and prompt pruning of affected growth can help manage these problems.

Choosing the Right Variety for the Space

Not all clematis are the same size or style. Some varieties stay compact and are perfect for containers or small spaces, while others grow several metres high and need strong support. If you’re planting near a trellis, archway or pergola, go for a vigorous grower like Clematis montana or Clematis jackmanii. For smaller gardens or patios, compact types such as Clematis ‘The President’ or Clematis ‘Arabella’ are better choices. Matching the variety to your space ensures the plant grows well without becoming unmanageable.

Sunlight and Shade Considerations

Clematis prefers a balance of sun and shade. While most varieties love full sun, there are some—particularly the spring-flowering types—that do well in partial shade. The one constant is that the base of the plant should be shaded. This can be achieved by planting groundcover plants around the base or placing a stone or tile near the root zone. Shading the roots helps prevent overheating and water loss during warmer months.

Soil pH and Drainage

Clematis prefers a neutral to slightly alkaline soil. If your soil is acidic, you can add a little garden lime to bring the pH up. What’s even more important is drainage. Clematis won’t tolerate soggy conditions, especially over winter. If your soil is heavy clay or slow-draining, dig in grit and compost to lighten it, or consider planting into a raised bed or large container. A well-drained site helps avoid root rot and crown diseases.

Supporting the Plant from Day One

Clematis needs a structure to climb, and it’s best to have that support in place before or at planting time. Unlike ivy or climbing hydrangea, clematis doesn’t cling with suckers. It wraps its leaf stems around thin supports, so wide trellis or thick poles won’t work as well. Thin wires, mesh or lattice frameworks allow the plant to climb more naturally. Installing these early avoids damaging roots later on and helps train the plant in the direction you want it to grow.

Establishment Takes Time

Clematis often follows the saying “first year sleep, second year creep, third year leap.” This means it may look underwhelming in its first season, as it focuses on root development. In the second year, you’ll get more noticeable growth, and by the third, it should be well-established and flowering strongly. Don’t be discouraged by slow early progress. Good planting practices, consistent watering and feeding will pay off over time.

Container Planting Tips

Clematis can thrive in large pots if you choose the right variety and give it the right care. Use a container at least 45 cm deep with good drainage holes. Add broken pot pieces or coarse gravel at the bottom to improve drainage. Use a loam-based compost mixed with perlite or grit for structure. Feed container-grown clematis regularly and water more often during warm weather. A stable, tall stake or trellis should be installed in the pot for support.

Cold Protection for New Plants

Newly planted clematis are vulnerable to cold snaps, especially in early spring. If a sudden frost is forecast, protect young shoots with fleece or an upturned plant pot overnight. Once the plant matures, it becomes more resilient, but frost can still damage tender growth. Spring-planted clematis often benefits from light protection in its first season to ensure strong, uninterrupted development.