Pruning immediately after planting is known as formative pruning, as it directs the future shape of the plant. The aim is to develop a balanced structure of branches with an even spread of foliage, flowers or fruit.
Because plant growth hormones are concentrated in the shoot tips, shortening or removing stems redirects hormones to produce more and stronger shoots, so weak stems should be pruned hard and vigorous ones lightly.
Unpruned growth can become long and straggly; the exception is where a tree or shrub has a single main stem or ‘leader’, which shouldn’t be touched. The amount of pruning depends on plant type: deciduous hedging plants, raspberry canes and currant bushes are cut hard back all over, while most trees and shrubs need selective, formative pruning. Newly planted rambling roses like a formative prune to encourage growth from the base, but hard pruning of other types of rose is generally done in late winter.
Discover our step by step advice on formatively pruning a deciduous shrub, below.
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This shrub (Clethra) has a good framework of branches, but with too much tall, leggy and thin growth. If left untouched, the bush would become very congested once in leaf next spring.
Shortening the strong, tall and leggy stems has two benefits – removing the main shoot tips will stimulate strong, bushy growth for the future and during the coming winter, and it lessens the overall height, which reduces the risk of wind rock.
Cut back to just above a well-placed bud, choosing an outward-facing one as this will encourage the development of an open-centred, vase-shaped shrub. Cutting above inward-facing buds would result in a poor shape with a congested centre.
Any shoots growing in the wrong direction; such as inwards, downwards or at right angles – should be removed completely. Cut close to the main stem to avoid leaving ‘spurs’ that will die and possibly become diseased. Thin, weak shoots should also be removed.
After formatively pruning a deciduous shrub, it should have a well-spaced framework of stems. All the thin, weak and badly placed shoots have been removed.