Box (buxus): when and how to prune

Buxus sempervirens

Clip a box hedge, ball or topiary twice a year: in late May or June, and from late August to early September, each time in dull, dry weather.

Box grows slowly, takes tight clipping better than any other shrub and even regrows from old wood. These days most of the work is not the clipping itself but spotting box tree moth and box blight in time: if you also look inside the shrub every time you clip, you catch them early.

Updated on 10 October 2026

Key facts
Pruning months	May–June and August–September
Nesting season (15 March–15 August)	Take care in May–June and August
Flowering	March–April
Good for bees, butterflies and birds	Little
Native to Belgium	Yes
Poisonous to people and pets	Yes, take care with children and pets

Box (buxus): when to prune it?

The first clip comes in late May or June, once the new shoots have finished growing. Clip earlier and the shrub carries on growing vigorously, so your crisp shape is soon lost.

The second clip is from late August to early September. After that, stop: the new growth still needs to harden off before winter.

Choose a dull, dry day: in bright sun the freshly exposed leaves scorch, and on wet foliage box blight takes hold easily.

What else to prune in those months? May · June · August · September

Box (buxus): how to prune it?

Use sharp shears: topiary shears for balls and shapes, a hedge trimmer for a long hedge. Disinfect the blades with alcohol before and during the job, especially between two hedges.
Before you start, part the branches. If you see webbing, little green droppings or green caterpillars with black stripes, box tree moth is present: pick off or vacuum up the caterpillars first.
Cut the new growth back to just above the previous cut. For a hedge, stretch a line; for a ball, a template helps, or walk slowly round the shrub.
Keep the top of a hedge slightly narrower than the base: the bottom then gets light too and the hedge stays dense right down to the ground.
Clear up the clippings straight away, including any caught in the shrub. Healthy clippings can go on the compost heap; clippings and leaves with box blight or caterpillars go in the general waste.
An overgrown or bare box can be cut back hard in late May, right into the old wood. It regrows slowly but surely; give it some compost afterwards, and water in dry spells.

How much to cut, and how often?

Two clips a year are enough for a crisp hedge, ball or topiary. A loose, natural-looking box needs clipping just once, after the first flush of growth.
Only ever remove the new growth. Cut deeper and you get bare brown patches that take months to fill in.
Let a young hedge gain only a few centimetres in height each year: it then branches well and stays dense to the bottom.

What does it mean for wildlife?

Few birds nest in a low box hedge, but blackbirds and dunnocks sometimes nest in large balls and taller hedges. The clip in late May or June falls in the nesting season (15 March–15 August): check first, as disturbing an active nest is against the law.
Don’t spray poison against box tree moth: chemical sprays also kill ladybirds, parasitic wasps and other useful insects. Tits and sparrows are eating the caterpillars more and more; a tit nest box nearby helps.
A biological product based on Bacillus thuringiensis works against young caterpillars, but also kills the caterpillars of other butterflies and moths: use it only on the affected box, and not when it is windy.
Box that isn’t clipped too tightly flowers in March–April with tiny scented flowers: early nectar and pollen for honeybees. If you are fighting box tree moth every year, switch to Japanese holly (Ilex crenata) or native yew.

Common mistakes

Clipping in full sun or in hot weather, so the leaves scorch and turn brown.
Clipping in wet weather or with dirty shears, so box blight spreads from shrub to shrub.
Still clipping after early September: the young shoots don’t harden off and discolour or freeze in winter.
Only looking at the outside: box tree moth starts on the inside and is only noticed once the shrub is half bare.
Leaving clippings lying around or feeding them to animals: box is poisonous, including to horses, cattle and other grazing animals.

Caution: When clipping, look out for box tree moth caterpillars (green with black stripes) and their webbing. Box (buxus) is poisonous: wear gloves and keep clippings away from children, pets and livestock.

Nearby: related pruning guides

Plant profile: Box (buxus) · Pruning calendar and basic rules