The Leyland cypress (× Cuprocyparis leylandii) is commonly used as a fast-growing hedge or screen. While it is highly effective in providing privacy and shelter, if left unpruned, it can grow out of control, become difficult to manage, and cause issues like shading and soil drying, which can affect nearby plants. Pruning your Leyland cypress properly ensures it remains manageable and healthy. Here’s a step-by-step guide to pruning Leyland cypress.
Quick Facts:
- Suitable for: All cultivars of × Cuprocyparis leylandii, Chamaecyparis lawsoniana (Lawson cypress), and Cupressus macrocarpa (Monterey cypress).
- Pruning Time: April to August.
- Difficulty: Moderate.
When to Prune Leyland Cypress:
Prune Leyland cypress during its active growth period, which is between April and August. Be mindful of bird nesting season; check for nests before pruning, as it is illegal to disturb or destroy nests under the Wildlife & Countryside Act 1981.
How to Prune Leyland Cypress:
Formative Pruning for Young Hedges:
- Year 1: At the start of the growing season (April), trim back any overlong side shoots. In July, trim lightly again, and tie in the leader shoot (the central stem) to a supporting cane to encourage dense growth.
- Year 2: Continue trimming side shoots to promote dense growth and maintain a tidy appearance over winter.
- Subsequent Years: Continue trimming the side shoots but avoid trimming the top until the hedge reaches the desired height.
- Once Desired Height is Reached: In the spring of the next year, shorten the leading shoots to about 15 cm (6 inches) below the required height to encourage thick top growth.
Pruning Established Hedges:
- Prune up to three times per growing season, from April to August.
- Shaping: Trim to form an inverted wedge (A-shape) with a flat top. This shape allows sunlight to reach the lower parts of the hedge, preventing the base from becoming bare and brown.
Pruning Overgrown Hedges:
- Leyland cypress grows rapidly and can quickly become overgrown if not regularly pruned.
- Healthy plants usually respond well to a reduction of up to one-third of their height. Do this in early April, just before new growth begins.
- Avoid reducing more than a third of the height in one go, as this can result in bare, flat-topped hedges or even the death of older, less vigorous plants.
- If you need to reduce the height by more than one-third, it’s best to do it in stages: reduce one-third initially, let the plant recover, and then cut back the remaining height.
Reducing Width:
- When reducing the width of the hedge, avoid cutting into older, leafless growth, as new growth won’t sprout from bare wood. Focus on trimming the outer, newer growth.
Pruning High Hedges:
Leyland cypress can grow to significant heights, leading to problems with neighbors due to shading. If your hedge becomes too tall, pruning can help manage its height. Under the Anti-Social Behaviour Act 2003, neighbors affected by tall hedges can now resolve the issue without legal action, provided the hedge significantly impairs their enjoyment of their property.
Problems to Watch Out For:
- Brown Patches: Always prune during the growing season to avoid cutting into older, leafless growth, which can cause brown patches.
- Skin Irritation: Leyland cypress can cause skin irritation, so wear gloves and long sleeves while pruning.
- Pests: Cypress aphids can infest the hedge, leading to brown areas of foliage. Regular monitoring and pest control can help prevent extensive damage.
By following this pruning guide, you can maintain a healthy and attractive Leyland cypress hedge while preventing it from becoming overgrown or problematic. Pruning will also encourage dense growth and help keep your hedge looking neat and tidy.