Hedging and topiary
How to grow box hedging and topiary
Buxus sempervirens
Box grows in sun or shade in any fertile, free-draining soil and is planted from October to March, 10 to 15 cm apart for dwarf edging or 25 to 30 cm for a low hedge. Clip in early June and again in late summer, always on a dry, dull day. The plant itself is easy; the two things that now decide success are box blight and box tree caterpillar, so keep the hedge open to air, clip in dry weather and inspect it from April to October.
- Hardiness
- Fully hardy
- Position
- Sun to shade
- Soil
- Fertile, free-draining
- Ideal pH
- 6.5 to 7.5
- Water
- Moderate
- Feeding
- Moderate feeder
Sowing and planting box hedging and topiary
WhenPlant Oct to Mar; clip Jun and Aug to Sep on a dull day
Starting off
Plant bare-root or root-balled hedging Oct to Mar, pot-grown stock any time it is not frozen or in drought. Propagate by 8 to 10 cm semi-ripe cuttings in Aug to Sep in gritty compost in a cold frame, rooting over the winter and ready to plant out the following autumn; hardwood cuttings 15 cm long in Oct also root. Where blight is a worry, try B. microphylla 'Faulkner' or Ilex crenata as an alternative.
Spacing and planting
Unclipped B. sempervirens makes a 3 m by 3 m shrub; as edging it is held at 15 to 45 cm, as a hedge 60 to 120 cm. Plant dwarf 'Suffruticosa' edging at 10 to 15 cm apart (7 to 10 per metre) and B. sempervirens hedging at 25 to 30 cm (3 to 4 per metre) in a single row, with the rootball top level with the soil. Excellent in a 30 to 45 cm pot of loam-based compost for topiary balls and cones.
Varieties worth growing
- Buxus sempervirens
- Common box, the one for hedges from 30 cm to over 1 m and for balls, cones and spirals. Sold bare-root in winter for hedging, which is far cheaper than pots.
- B. sempervirens 'Suffruticosa'
- Dwarf box for knot gardens and edging held at 15 to 30 cm. Very dense, which is its appeal and also why it is the form most prone to blight.
- B. sempervirens 'Elegantissima'
- Slow, compact, with cream-edged leaves; makes a neat dome or small cone without much clipping.
- B. microphylla 'Faulkner'
- Glossy, broader leaves and a more open habit; generally less troubled by blight than 'Suffruticosa' and good for balls and low hedges.
- Ilex crenata 'Dark Green'
- Not a box but a small-leaved Japanese holly, the usual stand-in where blight or caterpillar have made box impossible. It prefers neutral to acid soil that does not dry out.
Box hedging and topiary month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Plant bare-root hedging when the ground is not frozen.
- February
Plant bare-root. Brush snow off topiary before it splays the shape.
- March
Last month for bare-root planting. Hang pheromone traps for box moth.
- April
Feed and mulch. Start checking inside the hedge for caterpillars.
- May
Renovate overgrown plants late in the month. Do not clip the soft spring growth yet.
- June
Main clip in early June on a dry, dull day. Light feed afterwards. Water in dry spells.
- July
Check for caterpillar webbing and blight patches after wet weather.
- August
Second light clip from late in the month. Semi-ripe cuttings in a cold frame.
- September
Finish clipping by mid month so regrowth hardens before frost. Second caterpillar generation feeding.
- October
Plant. Hardwood cuttings. Clear fallen leaves from under the hedge.
- November
Plant bare-root. Take traps down.
- December
Plant in mild spells. Nothing else to do.
Feeding box hedging and topiary
A moderate feeder, because every clip removes the leaf the plant has just paid for. A balanced feed in April and a lighter one after the June clip keeps it dense. Avoid heavy nitrogen: soft, sappy growth is what blight likes best.
A balanced, slightly nitrogen-leaning feed in spring keeps the foliage dense and green.
Feeding plan
Planting
Dust bare roots before they go in, or use 5 g per litre of rootball for pot-grown plants: 10 g for a 2 litre pot. Once only.
April, hedges and edging
100 g/m². For a hedge that is 100 g per metre run, scattered over a strip 50 cm either side; for low edging use a 25 cm strip either side and 50 g per metre. Water in, then mulch with garden compost.
June, after the clip
Half the April amount: 50 g per metre of hedge, 25 g per metre of edging. Nothing after July.
April and June, pots
2 to 4 g per litre of compost scattered on the surface and watered in: 30 to 60 g for a 30 cm pot (about 15 litres), 80 to 160 g for a 45 cm pot (about 40 litres). Use the lower figure in June.
May to August, after caterpillar or blight damage, every 2 to 3 weeks
1 g per litre of water as a drench at the roots, to help a cut-back plant regrow. Keep it off the foliage where blight is present.
The live entry suggests a nitrogen-leaning feed and lists Garden Lime. This plan uses the balanced 4-4-4 only, to avoid the soft growth that favours blight, and leaves lime out because the label says to lime only after a pH test.
Signs to watch
Orange-bronze leaves in late winter → cold, wind and root stress, often with nitrogen hunger in tightly clipped hedges → a balanced feed in Apr and a compost mulch; colour returns by Jun. Pale yellow-green foliage and thin growth after years of clipping → nitrogen exhaustion → nitrogen-leaning feed at 100 g per metre run in Apr and again after the Jun clip. Yellow leaves with green veins on very a
Pests, diseases and problems
Brown patches spread through the hedge in wet weather, leaves fall to leave bare twigs with black streaks, white spores under the leaves in damp spells
Box blight, a fungus that thrives in humid, dense growth
In dry weather cut affected growth back to healthy wood, bag it, clear the fallen leaves and scrape off the top layer of soil beneath. Clean shears between plants. Afterwards clip less often and only in dry spells, water at the base, and mulch to stop rain splashing spores back up.
Webbing drawn over the foliage with green-yellow, black-striped caterpillars and pellets of frass inside; leaves eaten to skeletons
Box tree caterpillar, active from about March to October in two or three generations
Part the foliage and look inside from April onwards. Hand-pick on small plants, hang a pheromone trap to tell you when moths are flying, and spray caterpillar nematodes into the hedge on a mild, damp evening. Stripped plants usually regrow if the bark is intact; feed and water them.
Leaves turn straw-coloured and stay on the twig, with pink spore pustules under the leaves in damp weather
Volutella blight, which enters through clipping wounds and stressed growth
Cut out to green, healthy wood in dry weather and bin the prunings. Keep the plant fed and watered so it is not under stress.
Shoot-tip leaves cupped together like tiny cabbages in spring, with white waxy threads
Box sucker, a sap-feeding insect
No treatment needed on a clipped plant. The June clip removes the damage.
Whole sections of an established hedge yellow, thin and die where the ground lies wet
Phytophthora root rot
Remove dead plants with their soil, sort out the drainage, and do not replant box in that spot.
Pruning
Pruning and care
Clip once in early Jun after the spring flush hardens and again in Aug to Sep, 1 cm into the new growth, on a dull dry day; never clip in hot sun or before late May, when cut leaves scorch. Keep the hedge slightly wider at the base than the top. Overgrown box renovates well in May, cut back to 15 to 30 cm from the old framework, then fed and mulched; it regrows within 2 years. Water in dry spells, mulch
Good to knowClip in summer (avoid hot sun, which scorches cut leaves); feed and mulch to keep it vigorous.
Growing box hedging and topiary in pots
Box balls, cones and spirals live for many years in pots. Use a 30 to 45 cm pot of loam-based compost, with the rootball level with the surface, and turn the pot a quarter every few weeks so all sides get light. Pot-grown box goes orange-bronze when it is hungry, dry or pot-bound, so water through summer, feed in April and June and repot every three years. Water the compost, not the foliage, and stand pots where air moves round them.
Box hedging and topiary: common questions
When should I trim a box hedge?
Clip in early June, once the spring growth has firmed up, and tidy again in late August or early September. Choose a dry, overcast day: cut leaves scorch in hot sun, and wet weather spreads blight through the fresh cuts.
How do I tell box blight from box tree caterpillar?
Look for webbing. Caterpillar damage comes with silk webbing, green and black caterpillars and frass pellets, and the leaves are eaten away. Blight has no webbing: leaves brown and drop, leaving bare twigs with black streaks, and it spreads fastest in warm, wet weather.
Will box grow back after being cut hard or stripped by caterpillars?
Usually yes. Box shoots from old wood, so an overgrown plant can be cut back to 15 to 30 cm in late May, and a plant stripped by caterpillars will releaf if the bark has not been eaten. Feed, water and mulch it, and expect a couple of years for full recovery.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.
- How to grow boxRHS
- Box blightRHS
- Box tree caterpillarRHS
- How to grow boxBBC Gardeners' World