When to prune yesterday-today-and-tomorrow in the UK

Prune yesterday-today-and-tomorrow in mid to late spring. RHS guidance puts evergreen pruning in mid to late spring, once the risk of a hard frost has passed. Cutting evergreens in a British winter exposes soft new growth to frost damage, which is why the timing sits later here than in milder climates.

Pruning itself is not illegal, but destroying an active nest is. Under the Wildlife and Countryside Act 1981 it is a criminal offence to damage or destroy the nest of any wild bird while it is being built or in use, and the RHS treats the nesting season as March to August, sometimes longer. Check yesterday-today-and-tomorrow for nests before cutting, and if you find an active one, leave that part of the plant until the birds have fledged.

After flowering, trim shoot tips back by one-quarter to shape the plant and remove spent bloom clusters. Cut any dead or crossing branches cleanly at their origin. Avoid cutting into old bare wood. Light tip-pinching of new summer growth encourages the branching that will carry next spring's flowers.

Once annually after spring flowering; light tip-pinching through summer. Yesterday-Today-and-Tomorrow blooms on both old and new wood, so prune lightly and selectively. A heavy prune removes the flower buds set on previous season's growth. Shape lightly after the main spring flowering flush, removing crossing or dead branches. Tip-pinch young shoots through summer to encourage compact, bushy growth for next year's blooms.

Most pruning guides online are written for US conditions and anchored to USDA zones. Britain's maritime climate gives milder winters but later, less predictable last frosts — from March in the south-west to mid-May in the north — so the RHS advises against winter pruning for most plants: it pushes out soft growth that a late frost then kills. Britain also has the nesting-bird law, which has no US equivalent.