How to: grow clematis

Photo - photolibary.com

One of the great rewards for enduring a cool climate winter is the flowers that bloom in spring, and clematis is one of our favourites. 

Attention-seeking flowers cover a romantically twining vine that sets off rose gardens and perennial borders beautifully. Not for temperate or tropical gardeners, this treat is only for those who garden where frosts really bite. Melissa King tells how its done.

There’s an elegance and exoticism about the big single star-like flowers of clematis that grabs attention. Many of the hybrids are extravagant and large-flowered, though there are also double-flowering varieties some, with blooms that are remarkably tulip-like.

Although the deciduous varieties are better-known, there are also evergreen types. Some clematis form shrubby plants, perfect for pots, others are vigorous climbers that can be grown up pergolas or through climbing roses and flowering apples. Some varieties also have very attractive seed heads so don’t be too quick to prune off the faded blooms.

Photo - photolibary.com

Try these tips for a spectacular flowering display: 

Spring is a good time for planting: choose a position where the roots are shaded but the top of the plant can grow into the sunshine.

Good drainage is vital, so treat heavy soils with gypsum and organic matter or grow the plants in large pots. The large-flowered hybrids can be planted deeper than normal to promote more resilient, multi-stemmed plants: remove some of the bottom leaves and bury the lower two or three nodes.

Clematis doesn’t like to dry out. Ideally the soil will be moist but never water-logged. Water deeply two or three times a week during summer, more in extreme conditions. Mulch in spring.

Apply a complete liquid food once a week from late winter-early spring onwards. When the flower buds are roughly the size of a pea stop fertilising and then commence again once the spring flush has finished.

Spring-flowering hybrids flower on older wood, so prune lightly in winter, and then more severely after blooming. They will re-flower late summer-autumn. Mid- and late-flowering varieties, however, produce blooms on new growth so should be pruned back hard in winter - to 20-30 cm above the ground. They put on growth quickly and will be flowering again in about eight weeks. If you’re unsure what you are growing, play it safe and stick to the first method of pruning.

Text: Melissa King