Pruning Spring-Flowering Shrubs After Blooming in the Garden

Why the Weeks After Flowering Matter Most

There is a moment in late spring when the garden seems to exhale. The forsythia has finished its brash yellow show, the flowering currant has dropped its last pink racemes, and everything is suddenly busy making leaves. That pause — the quiet gap between bloom and midsummer — is the single best window you will get all year for pruning spring-flowering shrubs, and it is a window that closes quickly.

The reason is simple enough. Shrubs that flower before midsummer almost always do so on wood grown the previous season. Those shoots have spent the winter ripening, storing energy, and forming the buds that opened in March and April. Cut them in autumn or winter and you are cutting away next spring's flowers. Cut them in May or early June, before the plant has committed to its new growth, and you have time on your side: the shrub pushes fresh shoots through the long, warm days of early summer, and those shoots have the whole season to harden and ripen ready for next year's buds.

Know Which Wood Your Shrub Flowers On

Before you take secateurs to anything, work out whether your shrub flowers on old wood or new. It is the difference between a generous plant and a sulking one.

• Old wood, spring flowering: forsythia, flowering currant (Ribes sanguineum), blackcurrant, deutzia, philadelphus, weigela, kerria, berberis, hawthorn, blackthorn and most of the wild hedge shrubs.
• New wood, summer flowering: buddleia, hydrangea paniculata, caryopteris, hardy fuchsia and roses that repeat-flower. These want late winter or early spring pruning, not now.
• Both, if you are lucky: some hydrangeas and a few repeat-flowering ribes will give you a second flush, but never rely on it for the main display.

If you inherit a shrub and cannot remember the variety, watch it for a full year. Pruning is a conversation, not a command.

Forsythia, Flowering Currant and Their Spring Companions

Forsythia is forgiving, which is why it survives neglect so well — and why it so often ends up as a leggy thicket with flowers only at the very top. Deal with it now, while the blooms are fading but before the new shoots have hardened.

• Take out up to a quarter of the oldest, thickest stems right down to the base. Use a pruning saw or loppers and cut cleanly, without leaving a snag.
• Shorten the remaining flowered stems to a strong, outward-facing pair of buds, taking off roughly a third of their length.
• Tie in or leave the strongest young shoots to carry next year's bloom. A forsythia trained this way becomes a fountain of arching stems rather than a thatch of dead twigs.

Flowering currant responds to a gentler version of the same treatment. Cut the flowered side shoots back to two or three buds from the older framework, and remove one or two of the oldest branches at ground level each year. Do not overdo it: Ribes sanguineum is a plant of graceful, curving growth, and if you shear it into a box you will lose both the flowers and the scent that makes it worth growing.

If you grow blackcurrant for fruit, prune differently. It crops best on young wood, so take out about a third of the oldest stems after picking, and leave the one-, two- and three-year-old growth to carry next season's berries.

Hedgerow Natives and the June Rule

Native hedging shrubs follow the same old-wood logic, with one important exception. Hawthorn, guelder rose, spindle, dogwood and field maple can all be lightly pruned straight after flowering, thinning and tipping rather than hacking back. If you want the berries and haws for wildlife, leave the trimming until late winter instead, sacrificing some shape for food.

Blackthorn and wild cherry are different. Both belong to the Prunus family and are vulnerable to silverleaf, a fungal disease that enters through pruning wounds. Prune them in June or July, when the spores are least active and the sap is rising strongly. For most of us, that means keeping blackthorn trimming to a minimum and doing it in high summer, after the sloes have set but well before autumn.

Renewal Pruning Without Losing the Shape

Gardeners often worry that cutting out old stems will leave a hole. In practice, the hole fills within a season, and the plant is better for it. Work to a rolling three-year cycle:

• Year one: remove the oldest third of the stems at the base.
• Year two: remove the next oldest third, plus any crossing or rubbing branches.
• Year three: remove the remainder, and start again.

Feed and mulch afterwards. A handful of blood, fish and bone or a bucket of well-rotted compost, spread over the root zone and watered in if the weather is dry, pays for itself in strong, flower-bearing new growth.

What to Do With the Prunings

Hedgerow crafts begin at the pruning pile. Straight shoots of hazel, dogwood and willow make excellent pea sticks, plant supports and bean poles — bundle them by length and store them dry, and they will last several seasons. Longer, pliable rods can be woven into small hurdles or edging panels; soak them for a day or two first if they are stiff. Birch and hazel twiggy tops tie neatly into besom brooms or rustic obelisks, and lengths of willow bark or soft string make the tidiest ties.

Anything too twiggy for craftwork should be stacked in a quiet corner. A habitat pile of mixed prunings shelters beetles, hedgehogs and overwintering insects, and slowly returns to the soil beneath it. And before you clear the lot, take hardwood cuttings from forsythia, flowering currant, dogwood and willow. Push 20–30cm lengths into a pot of gritty compost, leaving two buds above the surface, and by next autumn you will have free hedging plants to extend your own piece of hedgerow.

Prune now, and the garden repays you twice: once in tidy shape and useful material, and again next spring, when the buds you spared open in the sunshine.