How to grow and care for Leyland cypress

Leyland cypress is hardy, easy to grow and quick to create screening or a windbreak. However, trimming two to three times a year is essential to keep its growth in check.

Identifying Leyland cypress

Leyland cypress rapidly forms a tall and fairly slender, broadly columnar tree. Leaves are scale-like, borne in flat sprays, and give off a strong resinous smell when crushed. Clusters of small ball-like brown cones 2-3mm across are borne in summer and autumn. The species has soft, mid-green foliage, but the variety ‘Castlewellan’ has yellow-green leaves.

Size, height and spread of Leyland cypress

Leyland cypress grows extremely vigorously, easily reaching heights of 10m in as many years, and several metres wide. Older trees can attain heights of 20-40m, depending on growing conditions, and several metres wide. The rate of growth per year is around 75-90cm. However, regular trimming several times a year from an early age keeps Leyland cypress compact, restricting growth to as little as just 2m high.

How to grow Leyland cypress

Plant a Leyland cypress hedge in a single row in any reasonable soil in sun or partial shade. Ideally plant in autumn or early spring and water during dry spells during the first growing season. Trim two or three times a year to maintain a neat well-shaped hedge.

Where to grow Leyland cypress

Leyland cypress thrives in any reasonable soil except waterlogged or exceptionally dry ground. Site in sun or partial shade. Leyland cypress is hardy and tolerates exposed sites and coastal locations.

How to plant Leyland cypress

Plant into well-prepared soil, preferably during autumn so the hedge establishes before the next growing season. Set up a string line to ensure the hedge is straight and space plants 60-90cm apart. When planting Leyland cypress as a boundary hedge, place at least a metre away from your property boundary to allow space to grow and to give access for trimming.

How to prune Leyland cypress

Trim both the top and the sides of a Leyland cypress hedge, two to three times during the growing season, avoiding spring when birds are nesting. Make the last cut of the year in early to mid autumn. Cut the sides on a slight slope so the hedge is wider at the base than at the top: this allows even distribution of light and shedding of snow in winter.

To achieve the desired height when the hedge is young, allow growth to develop 45cm above the final level before cutting back. Take great care to observe safety precautions when using powered hedge trimmers and when working off the ground.
To tackle overgrown hedges, reduce the height to the desired level and trim the sides back as far as possible without cutting back into bare wood beyond the foliage.

Wear gloves, and clothes to protect the skin, as contact with foliage may cause skin irritations.

Pests and diseases of Leyland cypress

Brown patches varying in size from a few centimetres across to more than a metre, can be caused by several pests or diseases, or by trimming in hot, dry weather.

Damage caused by Cypress aphid appears in spring and summer. Sometimes greyish green aphids are visible but the brown patches often develop after these have gone. Encourage birds into the garden as they feed on the aphids.

The fungus Pestalotiopsis is most common during long spells of damp weather, causing brown patches and eventually die-back of whole branches. More common on weak or stressed plants, so improving growing conditions helps avoid this disease.

Trimming a hedge during spells of drought or extreme hot weather, or late in the autumn during cold spells, can also cause brown patches.