Short answer
Trim conifer hedges little and often during the growing season, and always cut into green growth. Most conifers, other than yew, do not regrow from bare brown wood, so cutting too deep leaves permanent brown patches. The RHS advises replacing an overgrown conifer hedge rather than renovating it.
Conifer hedges include leylandii, Lawson’s cypress and western red cedar. They are fast and dense, but unforgiving.
Recommended timing (RHS)
| Hedge | Trims |
|---|---|
| Leyland cypress | 2-3 times in the growing season |
| Lawson’s cypress | Twice: spring and summer |
| Western red cedar (Thuja plicata) | Spring and early autumn |
| Yew | Twice: summer and autumn (yew is the exception that can regrow from old wood) |
How to cut
- Check for nests first.
- Set a string line for the top and keep the top narrower than the base.
- Cut from the bottom up, so clippings fall clear.
- Take off only the soft, green new growth; leave a little green behind every cut.
- Clear the clippings and check the base for gaps or dieback.
If you have already cut into brown wood
The brown patch will not green over. Options include tying in nearby growth to cover small gaps, planting a screen in front, or replacing the hedge. Reducing the problem is easier than fixing it, so cut regularly.
Tool tips
A long-bladed trimmer makes straighter lines on big conifer hedges. See trimmers for large hedges. Wear eye protection: conifer clippings and resin can irritate skin and eyes.
Check for nests before you start; see our nesting season guide.