August 22, 2026 Dominic Loughran

Pruning Without Fear: The Principles That Cover Most Shrubs

Quick facts

Suitable for: most deciduous and evergreen garden shrubs, climbers and young trees
Timing: the four Ds at any time; spring-flowering shrubs after flowering; summer-flowering shrubs in late winter or early spring
Difficulty: Easy to Moderate; renovating an overgrown shrub is Moderate
You will need: sharp bypass secateurs, loppers, a pruning saw, and a cloth with disinfectant
The principle: you are removing wood to change where the plant puts its energy, not tidying it

Start with the four Ds

If you know nothing else about the plant in front of you, you can safely remove wood that is dead, damaged, diseased or crossing. It applies to every woody plant at any time of year, and it is impossible to do harm.

Dead — scratch the bark with a thumbnail. Green beneath is alive, brown is not. Cut back into live wood.
Damaged — wind-torn, snapped, or rubbed by a tie. Irish gales produce plenty.
Diseased — cankered, blackened or oozing. Cut back into clean tissue and bin the prunings.
Crossing — rubbing branches wear a wound in the bark and let disease in. Take out the weaker.

Do those four things and stand back; on many shrubs that is the whole job.

The one question that resolves most timing confusion

Almost every argument about when to prune comes down to one question: does this shrub flower on this year's growth, or last year's?

On last year's wood — the spring and early-summer flowerers. Next year's buds form on this summer's shoots, so prune straight after flowering. Prune in winter and you cut off the flowers you were waiting for.
On this year's wood — the midsummer and autumn flowerers. They make new shoots in spring and flower on them the same year. Prune in late winter or early spring; the harder you cut the stronger the shoots.

That single distinction replaces about thirty separate rules. In an Irish spring, err towards March rather than February: a shrub pushed into soft growth by a mild fortnight is badly checked by the cold wet spell that follows.

Where to make the cut and why

Cut about 5mm above a healthy bud, sloping gently away so water runs off. Further out and you leave a stub that dies back; closer and you damage the bud.
Look at which way the bud points, because the new shoot will go that way. An outward-facing bud opens the centre to light and air, which matters in a damp climate. On opposite-budded shrubs, cut straight across just above the pair.
On a branch, cut back to a side branch, a bud, or the branch collar — the swelling where it meets the parent stem. Never leave a stub in mid-air, and never cut into the collar.
Make one clean cut with a sharp blade, and never paint the wound with sealant.

Formative, maintenance and renovation

Formative pruning happens in the first two or three years and sets the framework — one clear leader on a tree, an open evenly spaced structure on a shrub, no narrow forks to split later. Maintenance pruning is the annual routine: the four Ds, the timing rule above, and thinning the oldest quarter of the stems so young wood comes through.

Renovation is for a shrub gone bare and leggy at the base. Many take a hard cut to within 300 to 450mm of the ground in late winter — Cornus, Buddleja, Philadelphus, Viburnum tinus, laurel, box and yew all regenerate from old wood. Spread it over three years, a third of the stems each year, then feed and mulch. Most conifers other than yew will not shoot from bare wood, and Cytisus and lavender resent it too.

Tools and hygiene

Bypass secateurs cut cleanly; anvil types crush. Loppers up to about 25mm, a saw beyond. Keep everything sharp; a blunt blade causes ragged wounds. Wipe blades with disinfectant between plants, especially where you suspect disease; in a wet climate that is not fussiness. Clear prunings away rather than leaving them to reinfect the shrub.

A short reference list for Irish gardens

Prune after flowering, flowering on last year's wood: Forsythia x intermedia, Ribes sanguineum, Philadelphus coronarius, Deutzia, Weigela florida, Kerria japonica, Chaenomeles speciosa, Spiraea 'Arguta', Syringa vulgaris, Camellia japonica, Rhododendron and Escallonia. Cut flowered shoots back to a strong new shoot lower down, and take a few old stems out at the base.

Prune in late winter or early spring, flowering on this year's wood: Buddleja davidii, Hydrangea paniculata, Spiraea japonica, Caryopteris x clandonensis, Salvia yangii (formerly Perovskia), Fuchsia magellanica, Sambucus nigra, Ceanothus x delileanus 'Gloire de Versailles', and Cornus alba and Salix grown for winter stem colour.

One caveat: Hydrangea macrophylla flowers on last year's wood despite flowering in summer. Leave the old heads on over winter, then cut back to the first fat pair of buds in early spring.

Common mistakes

Pruning a spring-flowering shrub in winter and removing all the flowers.
Trimming lightly all over, which gives a dense outer shell and a bare dark middle.
Leaving long stubs above a bud, which die back and invite disease.
Reaching for the hedge trimmer on a shrub that wants selective cuts.
Never pruning at all, then trying to fix twelve years of neglect in one afternoon.

Most pruning mistakes are invisible within two seasons. Every principle here can be broken, once you understand it well enough to know why. If you are nervous about an old shrub, bring us a photograph and a piece of the wood.

Filed in: Planting & Care

Next article Watering New Plantings: How Much, How Often, and When to Stop

HOW MANY PLANTS?

First and foremost, you will need to consider the quantity of plants required to achieve a full looking hedge. We usually recommend 2.5 plants per linear metre for a fully mature hedge. For a semi mature hedge, you can plant 2 plants per metre.

However, different types of hedging plants have different growth habits, so the quantities of plants you may need could vary. it is always best to check with your local nursery.