How to Trim a Thuja Hedge

By Paul Watmore, Director at Grasslands Nursery

Trim a Thuja (western red cedar) hedge once or twice a year between spring and early autumn — and unlike Leylandii, Thuja can regenerate from older wood, so it is far more forgiving if you need to cut it back. A dense, aromatic and more manageable alternative to Leylandii.

When and how often to trim Thuja

Thuja (Thuja plicata) is fast but more manageable than Leylandii, needing one or two cuts between spring and early autumn to stay dense and to size. Leave the main cut until after nesting.

The key advantage over Leylandii

This is why many people choose Thuja: it can regenerate from older wood to a far greater degree than Leylandii. So while you should still trim mainly within the green, Thuja is much more forgiving of a harder cut, and an overgrown hedge stands a real chance of recovery. It also has soft, aromatic foliage that smells wonderful when clipped.

How to trim a Thuja hedge

1. Set a string line for a level top.
2. Keep a batter, wider at the base.
3. Trim the sides, then the top, keeping it dense.

Renovating an overgrown Thuja

Cut back harder than you would dare with Leylandii, in spring, then feed and water well; Thuja will usually break new growth from the older wood.

Thuja vs Leylandii

Thuja gives a very similar dense evergreen screen but grows a little more slowly, is easier to keep in bounds, smells aromatic, and — crucially — recovers from cutting back. For most gardens it is the more sensible choice. Browse our Thuja hedging and conifer hedging.

FAQs

When should I trim a Thuja hedge?
Once or twice a year between spring and early autumn, with the main cut after nesting.

Can you cut a Thuja hedge back hard?
Yes — unlike Leylandii, Thuja can regenerate from older wood, so it is much more forgiving of a hard cut. Renovate in spring, then feed and water.

Thuja or Leylandii?
Thuja gives a similar dense evergreen screen but is slower, easier to manage, aromatic, and able to recover from being cut back — usually the more sensible choice.

How fast does Thuja grow?
Thuja is fast (roughly 30–60cm a year) but more manageable than Leylandii, making a quick yet controllable screen.

About the author: Paul Watmore is a director at Grasslands Nursery, a family-run plant nursery near Knutsford, Cheshire, growing hedging, pleached trees and specimen plants since 1984. Meet the team →