Blackthorn: when and how to prune

Prunus spinosa

Prune blackthorn in winter (November–February) if it grows as a free shrub, and after flowering (June–August) if it is a hedge: now and then saw the oldest branches off at the base, and never prune everything at once.

Blackthorn is a native, thorny shrub of 1–4 m that is white with small flowers in early spring, before the leaves appear. It naturally grows in wide thickets: with its suckers it claims a little more ground every year. It needs little pruning. The work is mainly keeping the shrub in its place, replacing old branches and trimming a hedge, with sturdy gloves on.

Updated on 11 October 2026

Key facts
Pruning months	June–August and November–February
As a hedge	June–August
As a free-standing shrub	November–February
Nesting season (15 March–15 August)	Take care in June–August
Flowering	March–April
Good for bees, butterflies and birds	Yes, for bees, butterflies and birds
Native to Belgium	Yes

Blackthorn: when to prune it?

As a hedge

As a free-standing shrub

Prune a freely growing shrub or a field hedge in winter, November–February, while it is bare: you can see which branches are old, and you won’t disturb nesting birds.

Trim a formal hedge after flowering, in June–August. The bees have had the flowers by then, and the hedge still has time to fill out again before winter.

Don’t prune in early spring: you would cut off the flower buds, and with them the first nectar of the year and the sloes of autumn.

What else to prune in those months? January · February · June · July · August · November · December

Blackthorn: how to prune it?

Wear sturdy leather gloves and long sleeves. Blackthorn pricks easily become infected: disinfect a prick straight away.
On a free shrub, saw a few of the oldest, thickest branches off as low as possible every few years. Young branches that flower freely take their place.
Trim a hedge in summer, slightly narrower at the top than at the bottom, so the base gets light and stays dense.
Every year, dig out the suckers that come up outside the hedge or shrub, or mow them short in the lawn. With a piece of root attached, they make a new shrub for elsewhere in the garden.
Cut out dead branches, and branches that ermine moth caterpillars have stripped and that no longer sprout. Usually a stripped shrub simply leafs out again in summer.
A bare, old blackthorn can be cut right back to just above the ground in winter. It regrows vigorously, but flowers less for a year or two.

How much to cut, and how often?

A free shrub: a few of the oldest branches every few years. It needs nothing more.
A hedge: one trim a year after flowering is enough. Ideally don’t trim the whole hedge every year, but a section at a time, so there are always flowers and sloes.
In a field hedge, coppice the blackthorn to just above the ground every 8–12 years, a different stretch each time.

What does it mean for wildlife?

Summer trimming of a hedge falls in the nesting season (15 March–15 August). Whitethroats, dunnocks and even red-backed shrikes like to nest in a thorny blackthorn: look carefully first, and spare the stretch around an active nest.
The brown hairstreak, a rare butterfly, lays its eggs on the young twigs, where they stay all winter. So never prune everything at once, and always leave some of the young twigs.
In March–April the blossom is one of the first meals for wild bees, bumblebee queens and early butterflies. Dozens of kinds of caterpillar live on the leaves, food for young birds.
The sloes hang on well into winter for thrushes and blackbirds. Stack the prunings in a dead hedge: with the thorns in it, it makes a safe shelter.

Common mistakes

Pruning without gloves, and ending up with infected pricks.
Trimming a hedge in spring, so the flowers and sloes are lost.
Cutting the whole hedge short every year, including the twigs where the brown hairstreak’s eggs overwinter.
Leaving the suckers for years, until the blackthorn is in the lawn or the border.
Doing a summer trim without first checking for nests.

Caution: Before summer pruning, check that no birds are nesting, and never cut everything at once: the eggs of the brown hairstreak overwinter on the young twigs.

Nearby: related pruning guides

Plant profile: Blackthorn · Pruning calendar and basic rules