Trimming Western Red Cedar Hedges

Trimming Western Red Cedar

Trimming is the only necessary task requiring sheers, secateurs or electric trimmers. Western Red Cedar does not need pruning…

Western Red Cedar

Western Red Cedar 80-100cm
Western Red Cedar

When to trim?

As we have noted before, there is some disagreement as to when Western Red Cedar Hedges should be trimmed. However, this is a fairly redundant debate as Thuja plicata atrovirens AGM can be tidied up anytime from spring to early autumn. Also, any trimming is purely for aesthetic purposes – necessary if you want a neat formal hedge but entirely unnecessary from the plant’s perspective. If you’re not bothered by the neat and the tidy, you can just leave it to sort itself out.

How often to trim?

To keep this hedge in shape it will need trimming once or twice from late spring to early autumn. Trimming more often won’t do any harm but don’t leave too late to give it a late trim. The cut wood requires several weeks to recover and needs to do this before the cold and wet of winter sets in.


Western Red Cedar is a remarkably forgiving plant and as it doesn’t need pruning to give of its best (unlike, say, the Rose) there is no real technique to master. Unless you go mad and cut it all down, your hedge will take pretty much anything in its stride – including having its old wood cut into. Do that to a Leylandii and it will probably fail to recover.

This makes this hedge plant among the easiest of all hedging plants to maintain and manage. These are essential attributes if a plant is to receive the RHS’s AGM – an award that this hedge has and deserves. Its other requirements are equally simple and we’ll be looking at these in the next post…