Pruning is an important task in late summer, especially for perennial plants and shrubs that have finished their blooming cycle. Regular deadheading to remove faded flowers and browned flower stems helps to encourage new growth and extend the blooming season.
Not only will plants look fresh and tidier, but it will also trick the plants into channelling their energy away from seed production and into forming new flowers instead. Depending on the type of plant you are deadheading, either use a sharp pair of secateurs or flower snips or use your finger to pinch out the spent flower heads.
Early-flowering perennials
Perennials that bloom in spring or early summer, such as oriental poppies, centaurea or perennial cornflower, symphytum or comfrey, and pulmonaria benefit from being cut back hard, in early to mid-July, to near ground level if they look untidy or the leaves and old flower stems have become covered in mildew. They will quickly produce neat mounds of fresh, new foliage and, sometimes, another flush of flowers will emerge.
Most hardy geraniums begin flowering in May and June and by now the foliage of some early-flowering varieties has begun to look ragged. Around mid-July, use a shears to cut the flowered stems and tired-looking foliage right down to within 5-8cm of the ground.It seems a bit drastic, and while the plant will look bare for a while, but within a few days it’ll start to recover and respond by producing a fresh crop of attractive, more compact foliage, followed sometimes by a sporadic reblooming depending on the variety.
Pruning early-flowering shrubs
Several late spring and early flowering shrubs can be pruned immediately after blooming to promote new growth that will produce next year’s flowers. Deciduous shrubs to prune in summer include ribes, forsythia, weigela, kolkwitzia, spirea, deutzia, kerria and the wonderful smelling philadelphus, or mock-orange, the flowers of which are just going over now. Shape the shrub by shortening shoots that have flowered to around a half to one-third of their length, cutting just above a set of buds.
For the full article and lots more pruning tips for the garden pick up the Late Summer Issue 2024 of The Irish Garden magazine or subscribe here.
