Well grown clematis in containers are a welcome sight in any garden - big or small. Use them on the patio, stand them amongst other plants in the garden to create that instant impact, place them along walls or fences where no facilities exist for planting directly into the soil, or simply enjoy them in a glasshouse or conservatory.

Containers

Type

Containers made from wood, stone or earthenware (terracotta) provide excellent root protection against summer heat and winter cold. While containers made from plastic fail to insulate the roots of clematis when subjected to extremes of temperature, they can give years of trouble-free service provided they are sited very carefully.

Special attention should be paid to ensure that the holes for drainage are adequate. If necessary, the existing holes should be enlarged so that the clematis roots do not become waterlogged.

Size

Your container should be at least 45cm (18") deep and 30-45cm (12-18") wide. The larger and deeper the container, the better.

Compost

A rich, moisture-retentive but free-draining mixture is essential. John Innes No. 3 soil-based compost with added grit and humus is excellent for long-term pot culture.

Supports

Free-standing container clematis should be given proper supports made of metal or wood to prevent or limit wind-rock which will cause root damage.

After-care

From early spring onwards, container-grown clematis will demand regular attention.

Tying-in

Training and tying-in the new growths each week during the growing season will help to achieve the desired shape to show off the flowers and to prevent the plant(s) from becoming a tangled mess.

Watering

Watering is absolutely essential and must be done thoroughly. It is important to keep the containers well-watered from early spring until late autumn. Thereafter, simply keep the compost moist and prevent it from becoming dry and dusty.

Feeding

Every fortnight use a liquid feed (root and foliar) which contains equal parts nitrogen and potash. This will help to ensure a healthy and disease-resistant plant. Stop feeding as soon as the flower buds begin to show and recommence once the flowering period is over and continue until mid-August. With very late flowering cultivars, wait until the next spring before restarting the feed.

Pruning

Prune as for a clematis grown in open ground.

Adapted and abridged from BCS Fact Sheet No. 3 Notes on Growing Clematis in Containers by Mike Brown and Mary Toomey