Pinesap – an intriguing American and British native
The latest new plants

How to kill a Leyland hedge

Leyland Cypress, hedge. Image ©
Leyland cypress is a really useful hedging evergreen. It grows quickly, it’s a good color for a background to flowers, and it makes an effective screen and windbreak. The problem is that it keeps growing and growing and growing. Even on poor soil it can grow 3ft/90cm a year. The tallest is over 130ft/40m tall and still growing. And so, of course, it has to be trimmed regularly to keep it to a modest size.

With regular trimming you can keep it to very reasonable 6-8ft/1.8-2.4m high. But if you let it go for a few years, and then try to cut it back hard – this is what happens (above, click to enlarge). Not a pretty sight.

Why not plant an Arborvitae, Thuja occidentalis ‘Smaragd’ (sometimes known as ‘Emerald Green’), instead? It’s a good colour, less vigorous but not slow, and needs much less trimming to keep it to a manageable height.

Plant name note (deep breath, please): Leyland cypress was for many decades known botanically as xCupressocyparis leylandii – a hybrid between the Californian Cupressus macrocarpa and the Alaskan Chamaecyparis nootkatensis. The hybrid generic name combines of the generic names of the two parent plants, which helps grasp what’s going on. Ah, but then…

Ten years ago botanists decided that Chamaecyparis nootkatensis was so distinct from other species of Chamaecyparis that it needed a genus of its own, so it became Xanthocyparis nootkanensis. Then a few years later, after further botanical brain boiling, another generic name, Callitropsis, was proposed.

If that wasn’t confusing enough, whenever Chamaecyparis nootkatensis is put in a different genus the botanical name of the hybrid, Leyland cypress, must also change. So, if you think Chamaecyparis nootkatensis should really be Xanthocyparis nootkanensis then Leyland cypress becomes ×Cuprocyparis leylandii. But if you think Chamaecyparis nootkatensis should really be Callitropsis nootkatensis, then you probably also think Cupressus macrocarpa should be Callitropsis macrocarpa – which makes the Leyland cypress become Callitropsis x leylandii! Got that? Have I got that right (steam comes out of his ears)?

No no, hold the rotten tomatoes... it’s not my fault... It’s the rules!