Gardening: Prune to get on hedge of glory

It is still too early to be concerned with many deciduous plants, but it is a good time to answer one of the questions we were asked last month – how can I keep my evergreen hedge under control and is it too early to prune it?

In Edinburgh, many town gardens are surrounded by hedges planted to provide privacy, to mark the edge of a plot or simply to add interest. If left unclipped they can take over and shade small gardens, or create too much privacy and be a haven for burglars, or become too big so other plants struggle to compete.

Established hedges need to be pruned regularly to keep shape and density. This varies from once a year for the slow-growing yew (Taxus), to three or more times for the faster growing X Cupressocyparis leylandii and privet (Ligustrum). Hedges made up of shrubs with small leaves can be clipped with electric clippers, but larger leafed shrubs such as the spotted laurel (Acuba japonica) need to be pruned by hand.

Another client wanted to know if a new hedge can be rescued if it has been left to grow unchecked? His privet hedge was healthy but leggy and looked like separate bushes rather than a cohesive hedge. The answer was to cut it back by about a half to one-third in late spring and then repeat the process in the following late autumn or winter. This will help to establish a dense hedge without the base being bare. If you have an old established hedge it can also be restored, but not if it is a conifer such as X Cupressocyparis leylandii. Other shrubs can be restored in stages by cutting back hard on one side in one year and then the other side the next, not forgetting to keep the first side trimmed. After any hard pruning, ensure the plants are well watered and feed new hedges in spring and early summer.

Next month we’ll be helping to answer questions set by a balcony gardener.

• Jackie Macdonald is a partner in Small Green Spaces, which specialises in gardening for urban spaces using locally and ethically sourced materials, www.smallgreenspaces.co.uk