Gardens

How to grow clematis

Use our expert guide to find out how to plant and grow clematis successfully

Large group of clematis cirrhosa flowers
(Image credit: Getty Images)

Clematis produce an abundance of color and scent. There is a different type of clematis for every month of the year – and many of them can be planted now. 

If you love clematis – and, we don't blame you, they are some of the best climbing plants you can put into your backyard – grow a variety of species to enjoy their bloom 365 days of the year. 

Below, we tell you which varieties to choose for color, scented and coverage, when and where to plant them – and how to care for clematis.

Which clematis to grow?

Evergreen climber - clematis

(Image credit: Alamy)

Clematis are amongst the best climbing plants with flowers you can put into your borders – and there is a wide range of varieties to choose from.

Kicking off the show are the spring-flowering forms: C. alpina and C. macropetala; good cultivars include powder-blue ‘Wesselton’ and ‘Frances Rivis’. And come May, the sublime scents of C. montana and C. armandi, begin to perfume the air. 

Early summer sets the stage for the well-known big-flowered clematis, such as pink and white striped ‘Nelly Moser’; then, in July, the reliable C. viticella forms (such as ‘Madame Julia Correvon’) begin to bloom, as do fragrant stars C. x triternata ‘Rubromarginata’ and C. rehderiana. 

Fall is brightened by the sun-yellow bells of C. tangutica, and, as the year draws to a close, the white or maroon flowers of C. cirrhosa begin to open in the winter sun. 

CLEMATIS MONTANA 'RUBENS' with wisteria

(Image credit: Getty Images)

If you only pick one, the mountain clematis (C. montana) (above) is a good choice. Val Le May Neville-Parry, who holds the UK National Collection of C. montana, explains why: 'Montanas flower over a long period in the spring-summer lull, provide nesting for birds, and have heavenly perfume. Two of my many favourites are "Miss Christine" and "Van Gogh".' 

Montanas have an informal, romantic habit that lends them to being grown over summerhouses and sheds. The very large forms (referred to by Val as 'beautiful thugs') are ideal for concealing an unsightly garage or long fence.

When to plant clematis

clematis

(Image credit: Getty Images)

Clematis can be planted at any time of year, but ideally not when they’re in flower. Spring is the optimum time to plant forms that flower in late summer, fall, and winter; and the prime time to plant species that bloom in spring and early summer is fall. The winter season is also a good planting period, unless you live in a very cold climate. 

Where to plant clematis

Close-up image of a beautiful spring flowering, pink Clematis 'Mayleen' flower

(Image credit: Getty Images)

'Don’t plant too close to the wall, tree, or fence it is going to climb,' advises Val. 'It needs to be about 3ft (90cm) away. Clematis like well-drained soil that isn’t too dry and isn’t waterlogged.' 

The base of your clematis must be shaded (for example by shrubbery) to keep the roots cool, but the rest of the plant should climb into sun or semi-shade. 

How to plant clematis

These step-by-steps to growing clematis will ensure success.

1. Prepare for planting the clematis

Soak the plant by sitting the pot in water for an hour. 

While your clematis is soaking, prepare the ground. Clematis like deep, fertile, moist, well-drained soil, so dig well to loosen the earth and fork in organic matter (such as compost). 

2. Position the clematis

Lean the clematis at a 45 degree angle towards the wall or fence. 

Plant large-flowered cultivars 2 to 4in below the compost level they had in the pot. Most other clematis like to be planted just slightly below soil level.

3. Train the clematis

Provide a structure, such as trellis ideas or pergola ideas, for the twining stems to coil around as the plant climbs. 

Growing clematis in pots

Best climbing plants - clematis

(Image credit: Alamy)

Growing clematis in pots requires a large container to allow for healthy root growth, particularly in the more rigorous varieties. As with planting clematis in borders, soak the clematis first, then prepare a deep – at least 18in deep – hole in the pot, which should be filled with well-drained, rich soil mixed with plenty of organic matter. Position the clematis so that it can lean, either on a trellis behind the pot or against an obelisk or other support within the pot. Ensure the pot is shaded from hot sunshine – clematis like their roots shaded and they will be more vulnerable in a container than in the soil.

How to care for clematis

Water newly planted clematis regularly during dry weather. 

Feed with a potassium-rich fertilizer once a year. 

Mulch annually with well-rotted manure or organic compost. 

Protect young growth from slugs and snails.

Prune clematis according to the group your clematis belongs to. 

Pruning varies according to the type of clematis you are growing.