Spring-flowering shrubs, such as deutzia, physocarpus, philadelphus, forsythia and weigela produce their blooms on the woody stems made in the previous year. Cut out these stems as soon as the flowers have faded (or by July at the latest) and leave the current season’s new shoots to grow from the base.
Use secateurs to cut out all the woody, flowered stems. Prune back to just above vigorous green stems growing from low down on the plant.
For the thickest woody stems, or where shrubs have become very overgrown, use long-handled loppers or a garden saw to cut through the tough stems.