Posted: 15/09/2014 at 14:48
Pieris flower in early to id spring so fall into what the RHS classifies as pruning group 8. This just means prune lightly after flowering finishes. If you prune it now you risk frost damage to the remaining foliage and flower buds and also fewer flowers next spring.
Here is what the RHS advises:-
When to prune evergreen shrubs
You can prune most evergreen shrubs just before growth starts in mid-spring, after any risk of frost has passed. Pruning at this time will avoid frost damage to new shoots, and any pruning scars will be concealed by new growth.
Evergreens that are still flowering or about to flower in mid-spring can be left until flowering has finished.
How to prune evergreen shrubs
When pruning any evergreen shrub (except old, overgrown shrubs, see below), aim to remove about one-third of older wood in total.
- Prune out any diseased, damaged or dead shoots using long-handled loppers or a saw if necessary
- And finally, thin out crowded shoots and any badly positioned ones that spoil the shrub’s appearance
- After pruning, plants benefit from mulching and feeding. Use either a general-purpose fertiliser or specialist rose or other high-potassium fertiliser
For convenience, we have divided evergreen shrubs into three groups on the basis of timing and type of pruning required:
1. Early flowering evergreen shrubs (Pruning group 8)
Timing: Prune immediately after flowering.
Examples: Berberis, box (Buxus), Camellia, Ceanothus, Choisya, Daphne, Hypericum, Mahonia,Pieris, Azalea (Rhododendron), Rhododendron, Viburnum tinus.