Clematis: Queen of the vines

Often referred to as the queen of vines, clematis grows beautifully on its own or planted among perennials, with trees and shrubs, roses, other vines – even in containers. With more than 280 species of climbing and woody herbaceous species, mostly deciduous but some evergreen, the genus clematis contains a species suitable in various habitats.

If you know the origin of your species, you’ll have a good chance of recreating that environment in your garden. For instance, a species native to the European Alps, C. alpina, is persistently hardy in Canada’s climate extremes while C. flammula comes from the Mediterranean and may not do as well in colder climates.

The species clematis is the mainstay and comes with natural hardiness and resistance. Various types have different preferences from full sun to full shade, and most do well with fellow garden plants, especially roses for their firm base of support. But they can also be planted against a wall, near a tree trunk or an old tree stump.

Clematis flowers, which can be single, semi-double or double, do not have true petals but a group of sepals, often referred to as tepals. The rich colours oflematis range from deep purple to pale pink, white and cream.

For every season, there is clematis. First come the early flowering species: the hardy alpines, C. alpine, need little or no pruning and have clusters of little flowers; C. macropetala bloom in late spring to early summer; C. montanas are early summer clematis and do best in an English climate. C. ‘Elsa Späth’ and C. ‘Jackmanii’ are mid-season and late bloomers respectively.

Buying and planting

• Buy from a reputable garden centre or grower, and ask about pruning. Pruning time depends on whether the plant flowers on last year’s growth or this year’s new growth, but generally clematis will grow happily and faithfully with little pruning at all.
• Choose a plant that looks strong and healthy, with new young growth and a good root ball.
• Clematis thrives when its roots and lower stems are cool. Partner it with a low-growing plant close to the root ball or mulch the soil surface heavily.
• If planting next to a wall, make sure the hole is at least 10 inches (25 cm) away.
• Soak the root ball in a pail of rainwater for about 30 minutes before planting, especially if it was in a plastic pot.
• Fill the bottom of the hole with sticks for drainage, compost and a sprinkle
of phosphate for root growth.
• Transfer the entire contents of the clematis container (soaked root ball and earth) to the hole, setting the bottom of the main stem where it meets the root ball about 5 inches (12 cm) below the soil surface.
• Gently backfill the hole and tamp down with garden compost.
• Water clematis in full sun every day during spring and summer, but do not over water.
• During periods of rapid growth, fertilize with a mixture of steeped cow or sheep dung and water, or with fermented comfrey leaves or garden compost.