If there’s one thing you should remember about pruning flowering shrubs, it is prune straight after flowering. So those early summer flowering shrubs are pruned in midsummer. This year, if you are anything like me you are running late. Partially because of wet weekends, but also because some philadelphus, deutzia and weigela seemed to have flowered quite late, and over a long period. That’s my excuse anyway!
Summer pruning of these shrubs is quite an easy task. You just cut out some of the stems that have flowered, right back to where you see strong, vigorous new shoots arising low down on the stems. You do not have to do it every year, if you miss a year it’s not the end of the world. If you miss a few then you may have to have a good sort out to get a plant back into shape.
That’s what I did this year with one or two overgrown philadelphus. The sooner you prune after flowering the better because those new shoots are not too advanced. The later you leave it the more likely you are to damage the new shoots when you cut out the old.
Summer pruning is also carried out now on silver foliage subjects, especially santolina. whether you like the hard yellow flowers of Santolina chamaecyparissus or not, now is the time to cut them back; back to wherever you can see new shoots appearing on the stems. If you cut back into bare, older wood they may not regrow. Trimmed in this way now they should produce a new flush of silver foliage which will stay looking good through autumn and into winter. Leave those flowerheads on and the shrubs seem to fall apart and end up in a soggy heap.