TRIM HEDGES of Carpinus betulus (hornbeam) this month but treat new hedges gently. Hedges and screens of Crataegus monogyna (hawthorn) can be dealt with in the same way. If specimen trees of either kind need reducing in size, leave the work until winter when they are dormant.
RAMBLING ROSES, such as `Albertine' (pictured) and `Alberic Barbier', should be pruned as soon as they have finished flowering. The aim is to make them produce new wands of growth from the base, which will carry the following season's crop of flowers. Where ramblers are grown on pergolas, you need occasionally to untie old branches of rambling roses and cut them out to make room for fresh growth. It is not a pleasant job. Other roses that need this treatment are `Dorothy Perkins', `Emily Gray', `May Queen', `Sanders White' and `Veilchenblau'.
GRISELINIA, A New Zealand native with tough, leathery evergreen leaves, is sometimes used to provide shelter in seaside gardens. The plant is not reliably hardy, though it is wonderfully resistant to salt and wind. Where it is used to make a hedge it will need regular clipping, which should be done now. Shrubs planted as specimens need no regular pruning.
DEUTZIA, WHICH flowers in June and early July with clusters of small, star-shaped flowers can be pruned immediately after flowering. The best way to do this is to take out some of the old flowering stems, cutting them down at the base of the plant. This will encourage the production of strong new shoots from the base. It also keeps the shape of the shrub within reasonable bounds.
KOLKWITZIA AMABILIS (beauty bush) has tiny foxglove flowers on upright, arching stems. Treat it in the same way as deutzia, removing some of the old stems when the shrub has finished flowering. This will maintain a steady supply of young, vigorous growth.Reuse content