Tony Dickerson problem solves
QWhat’s the best way to prune my earlyflowering clematis? Kate Jackson, Middlewich, Cheshire
AClematis can be classed into three pruning groups, depending on when they flower. Early-flowering clematis, such as Clematis alpina and C. macropetala flower on shoots produced the previous summer. These clematis are in pruning group one.
They should be lightly pruned after flowering in mid-to-late spring to keep them tidy. Pruning is quite simple and just involves trimming back overlong shoots to a pair of healthy buds. Very vigorous clematis, such as C. montana, can be sheared over with hedge clippers after flowering. C. cirrhosa and most winterflowering clematis can also be lightly sheared or overlong shoots shortened. Where older plants have become congested and untidy, they can be renovated by cutting all stems back to 30cm (12in) from the base after flowering. Apply a general fertiliser, mulch and water in dry spells. This approach doesn’t work with C. armandii, which rarely regenerates from old wood. Instead, prune established plants to contain their growth to the space available. In spring, remove any leaves damaged by wind scorch over winter.
The large-flowered clematis in pruning group two, such as ‘Jackmanii’ and ‘Nelly Moser’, flower in May and June on short shoots growing from the previous year’s growth. They should be pruned in February, reducing longer shoots by no more than half.
If you missed the boat this year, some of the longest can still be shortened back now, but follow up with further pruning immediately after the first flush of flowers in early summer, taking off the faded flowers to a large growth bud immediately below the spent flower.
Clematis in pruning group three, such as ‘Gravetye Beauty’, ‘Étoile Violette’ and C. viticella, flower on the ends of the current year’s growth in late summer. Prune these ones back hard to 30cm (12in) or so from the ground in mid-February.
It doesn’t really matter if you miss a year, although the flowering will occur at a greater height from the ground. They can be brought back into line next February.