Shrubs create fantastic structure in the garden so it's essential to keep them in top condition with regular pruning. This improves a plant's shape and encourage flowers and fruits.
Cuts are essentially wounds to the plant where disease could enter so use sharp and clean cutting tools and make clean cuts without leaving snags. Cut close to buds, but not into them, and always just above.
Pruning early in the plant's life helps establish a shapely shrub with vigorous, balanced growth. In very young plants this is known as 'pinching out', literally removing by pinching the growing point on most if not all the stems.
Evergreen shrubs generally do not need thinning or formative pruning. However all shrubs benefit from reducing any excessively long shoots and removal of 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.
After a summer's growth, it's a good idea to give your shrubs a tidying prune in autumn to keep them in shaped. Once deciduous shrubs lose their leaves, it is easy to see the plants' overall shape and decide what needs to be cut back.
In regards to plants in pots - Once a potted shrub reaches maturity it is best repotted annually in spring, potting up into only a sllightly larger container. If you find the plant is very pot-bound, this is a good time to lightly prune the roots.
Remove about one-third of the thicker non-fibrous roots back to the 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.