Shrubs create the structure in a garden so it's important to keep them in good condition with regular pruning. This will improve a plant's shape and encourage flowers and fruits.
Pruning young shrubs
Early pruning helps establish a shapely shrub with vigorous, balanced growth.
Most evergreen shrubs do not need thinning or formative pruning. However all shrubs benefit from shortening any excessively long shoots and cutting out weak or damaged growth.
Deciduous shrubs are more likely to need pruning into shape; this is known as formative pruning. Young shrubs often grow lots of shoots so you will have to thin them early on.
Correct lopsided growth by lightly pruning longer shoots and hard pruning weak stems.
Rejuvenating old shrubs
Shrubs such as forsythia and buddleja can soon accumulate masses of old, dead wood in the centre if they are not pruned regularly.
The best way to rejuvenate these plants is to cut them back during the dormant season.
First cut out dead, diseased and crossing stems, and then thin the number of remaining stems by half.
Shrubs that respond to severe pruning, such as ribes and philadelphus, may be cut almost to ground level to re-establish a framework of new shoots. If the shrub is old and it's hard to predict a successful revival, take cuttings just in case.
Pruning shrubs in pots
Once a container shrub reaches maturity it is usually best repotted annually in spring, or every other year, using the same or similar sized container.
If you find the plant is very pot-bound, this is a good time to lightly prune the roots.
Prune about one-third of the thicker non-fibrous roots back to the intact rootball, but avoid damaging the fibrous feeder roots.
Repot in fresh compost and finish by pruning the top growth by about one-third to balance the root loss.
Coppicing and pollarding shrubs
Shrubs grown for their colourful stems or foliage, such as dogwood, need to be cut down every spring to 4-5 buds to encourage new growth.
This is known as coppicing. If you want to keep a framework of older stems, cut down one-third of stems.
A similar technique is called pollarding where stems are cut back to the same point a single stem or framework of stems. This is often seen on London plane trees and can be used on eucalyptus. After pruning, make sure you feed and mulch the plant.
Pruning shrubs in autumn
After a summer's vigorous growth, it is a good idea to give your shrubs a light prune in the autumn to keep them in shape.
Once deciduous shrubs lose their leaves, it is easy to see the plants' overall shape and decide what needs to be cut back.