Where to plant
Climbing plants, clematis need shade at the roots and like to get their heads into the sun where they produce their gorgeous blooms. They should be planted in a cool, shady moist site where their heads can reach the sunshine.
To reduce mildew, planting where there is a breeze or good air circulation is a plus, but planting in draughts of the full force of a southerly gale will result in tangled and broken plants strewn across the garden.
Grow on a wall or trellis, fence or frame, but also through shrubs and trees, taking care to choose hosts that can support the particular clematis chosen and will complement either the hosts flowers in season or provide a second season of interest.
Clematis trained 'on the flat' brings the flowers closer to us, and a balustrade makes a wonderful support while allowing us to get up close and personal with the blooms.
You can buy trellis, obelisks and other supports today, enabling you to use clematis to give height in your borders. Pergolas are a traditional support, although the flowers are overhead and on the sunny side of the pergola rather than underneath where we can see them.
- Wire or plastic mesh on a wall or frame
- Wires stretched across a wall
- Wire should be a minimum of 1.5cm (0.5in) from the wall to allow space for the leaves.
Clematis, probably 'Victoria', on a wall
In the border clematis can scramble through other plants and across the ground, use pea-sticks and canes to lift them.
Clematis can be grown in containers. The container must be 45cm (1ft6in) deep and wide as a minimum and good quality potting mix must be used. Use a surface mulch of gravel or bark to help keep the soil cool and conserve moisture. Regular watering is essential. Feed weekly with liquid fertiliser and give a handful of bonemeal in autumn.
Clematis for your garden
C. viticella, a small-flowered clematis from Spain was one of the earliest clematis introduced into gardens and flowers in late summer. Perfect for growing through shrubs, rhododendrons, roses and other early flowering hosts, C. viticella provides a second season of colour.
Typically C. viticella has purple saucer-shaped flowers with brown stamens that hang in profusion. 'Etoile Violette' is deep violet and a striking combination with pink roses or late flowering rhododendrons. 'Royal Velours' is darkest purple; 'Minuet' has cream coloured sepals shaded mauve. 'Abundance' is a glowing rich wine red. Lavender-blue Clematis 'Kermesina' is one of the best Vigorous and free-flowering, most will reach 3-6m (10-20ft). Hard prune in winter.
Clematis alpina 'Frances Rivis'
C. alpina (1.8m or 6ft), one of the earliest flowering clematis, has satiny blue nodding flowers in early spring making is a wonderful complementary planting with rhododendrons, or an unexpected colour note with the yellow daffodils and pink blossom of this season. Typically a scrambler, C. alpina is less vigorous than some clematis and can safely be used with roses and smaller shrubs. 'Frances Rivis' dark blue-purple, 'Helsingborg' is darker. 'Pamela Jackman' is deep blue with a white centre. 'Flamingo' is pink and 'Ruby' red, for white look for 'White Columbine'.
C. integrifolia is a herbaceous clematis. Summer blooming with nodding flowers of deep blue with white stamens it reaches 30-60cm (2-3ft). 'Durandii', with deep purple single flowers is semi-herbaceous, scrambling to 1.8-2.4m (6-8ft). Very popular, it combines well with pinks and yellows in the garden, or adds a deeper note to a magenta planting. Prune in winter.
Clematis 'Kermesina' grown over a balustrade
Clematis grown up a support
Clematis is best transplanted in winter when dormant. Prepare a new planting site first. Dig in plenty of organic material, and ensure that the planting hole is generous enough to take the rootball.
If the plant has become very tangled in its host or support, cut it back hard. Spring and summer flowering clematis will skip a flowering as a result, but you will get a late summer flowering on many clematis.
If you can, bundle the clematis stems and tie them together loosely while transplanting.
Dig up the clematis with as large a root ball as you can. Lift it with a sack or section of strong horticultural cloth underneath. Plant the clematis about 5cm (2in) deeper than previously to encourage new growth from the root.
Transplanted clematis will need plenty of water in the first year after moving, water twice weekly. Also watch for signs that the ground is not free-draining enough (a frequent cause of death) until the plant has re-established.
As with most other plants, pruning their clematis causes the onset of a severe anxiety attack in many gardeners. The clue to remember is that clematis that flower in summer on new growth need pruning. Leave the rest alone except to control their vigour or rescue their host or support from imminent collapse.
Clematis that flower on young wood (C. viticella and C. Jackmanii types) should be cut back to the last pair of buds. If they send out new shoots each year then cut to the ground in winter, and not later than the end of July (mid-August in cool areas).
Early flowering clematis should not be pruned or you will remove all the flowering wood and have no blooms in early summer/spring. Trim back the untidy, dead ends in Aug/Sept, cutting back to a pair of live buds.
Exercise restraint and caution, it is easy to trim 'dead' stems and then find healthy buds above when adding the 'dead' growth to the wheelbarrow.
Double clematis are not pruned, simply tidy these as soon as the blooms have finished.
The languiosa group of large flowered cleamtis, including C. 'Henryi', 'Mrs Cholmondeley' and 'Mme le Coultre', flower on last seasons ripened wood and should not be winter pruned. If there is no post-flowering tidy then there will be a second period of bloom, albeit with smaller flowers.
The very vigorous armandi and montana groups should be left unpruned although removing deadwood and tidying is beneficial. Prune only to reduce the weight of the plant which can easily collapse it support, to restrain growth and prevent these vigorous plants smothering their neighbours. It is best to do this immediately after flowering to allow new flowering wood to mature over summer.
The herbaceous clematis, C. heracleifolia and C. texensis are deciduous and die down in winter. Remove the dead stems in your autumn/winter cleanup when they should come away easily from the base of the plant.
And our own native clematis - leave well alone as these evergreen clematis resent being messed about with!