Gardening / Cuttings: Weekend work

TRIM hedges of Carpinus betulus (hornbeam) this month, treating new hedges gently and cutting harder into established ones. 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, do this in winter, when they are dormant.

Griselinia, a New Zealand native with leathery, evergreen leaves, is sometimes used to provide shelter in seaside gardens. It is not reliably hardy, though wonderfully resistant to salt and wind. Where used to make a hedge, it needs clipping, which should be done now. Shrubs planted as specimens need no regular pruning.

Deutzia, which in June and early July has clusters of small, star-shaped flowers (either white or shades of mauve and purple), can be pruned immediately after flowering. The best way is to take out some of the old flowered stems entirely, cutting them down at the base of the plant. This will encourage production of strong new shoots from the base. It also keeps the shrub within reasonable bounds.

Kolkwitzia amabilis (beauty bush) has tiny foxglove flowers carried on upright, arching stems. Treat it in the same way as deutzia, removing some of the old stems entirely when the shrub has finished flowering. This will maintain a steady supply of young, vigorous growth.

Rambling roses, such as 'Albertine' and 'Alberic Barbier' should be pruned as soon as they have finished flowering, rather than in the winter. The aim is to make them produce new wands of growth from the base to carry the following season's crop of flowers. Where ramblers are grown on pergolas, you need occasionally to untie old branches and cut them out to make room for fresh growth. It is not a pleasant job. Others that need this treatment are the old-fashioned rambler 'Dorothy Perkins', 'Emily Gray', 'May Queen', 'Sanders' White' and 'Veilchenblau'.