It’s Derby Day and the day in gardener’s diaries for box tree clipping!
This timing of box tree clipping and hedge trimming comes from way back when the family at the big house decamped to Epsom for that all important horse racing festival at the start of June. You see, trimming vast amounts of box plants was messy, required unsightly equipment and generally spoilt the view! So what better time to do it than when the house was empty?
It just so happens that early June is actually a good time for box tree clipping as the risk of late frost has diminished. New growth on box [Buxus sempervirens] can be surprisingly frost prone but can also bleach in strong sun when new growth is removed exposing shaded shoots below.
Box Tree Problems
There are a couple of serious threats to the health of box trees and whilst one is as yet over the horizon for most West Country gardeners [box tree moth], the other [box blight] is already here in our neck of the woods. Both are recently introduced to the UK and if left unchecked are devastating for box!
We’re afraid that control methods for both are limited and so it is essential to monitor your plants regularly for this pest and disease. What better time to do that than when you are up close and personal with a pair of garden shears?
You might see similar symptoms on your box for both ailments. Look for patches of dead leaves and sections of hedges that are dying back. The moth caterpillars – usually hidden within webbing- will confirm the box tree moth’s presence in your area. It’s already widespread in London! Pheromone traps can be hung to monitor for moths in the vicinity. If caught early enough, picking caterpillars off maybe enough but try also control with nematodes suitable for caterpillars. Insecticides will need to be thoroughly and forcefully applied to penetrate the webbing.
But back to box tree clipping; there is an aspect in how you do this to minimise the risk of box blight infection and spread. Avoid overly crowded growth. Allow as much air circulation around plants as possible so away with those perennial plants leaning against the neatly clipped hedge! Pick up and compost trimmings. Give your box bush a good shake to clear out dead leaf matter lodging inside. Make a habit of dipping your sharp shears into a bucket of water and mild sterilant. These measures minimise the likelihood of your trees becoming infected.
Alternatives to box
But what of the alternatives to those neat and formal box trees that we have loved and grown for centuries? Well there are a few and some come pretty close to box in their effect. The small-leaf Japanese holly Ilex crenata is the front runner. But you could try Lonicera pileata which is much faster growing. At Highgrove box has been replaced by bee friendly Teucrium x lucidrys. Some of the small leaf Hebe work and I’d suggest Hebe rakaiensis, subalpina or topiaria.
Perhaps you too have boxed clever and had success with other species. If so we’d like to hear from you!