What has gone wrong with my box hedging?

If you have smaller evergreen hedging that is suffering badly – it is likely to be a common problem – here we discuss how to recognise this and what to do about it!

The problem- box blight and box caterpillar

Box blight is a fungal disease that affects boxwood or “box” plants (Buxus sempervirens). It causes bare patches as shown in the image below. It first appeared in the UK in the mid 1990’s and has devastated parterre gardens (low hedging in funky patterns) and topiary (any clipped shapes particularly balls, pyramids and spirals).

You will see leaves turning brown and dropping, black streaks and die back on younger stems and white spores under the leaves. (There is a different blight variety that produces pink spores).

Box caterpillar on the other hand leaves your plants looking like a spooky brown cobwebby mess….

In both cases this can happen pretty fast, the caterpillar can do it almost overnight, and while there are some control measures (see RHS advice) for control of box blight and RHS advice for information on box caterpillar), they are all pretty onerous and it will be an ongoing task.

Should I give up the fight against box blight and box caterpillar?

If you have a gorgeous parterre garden or large box topiary that feels worth the time and effort to preserve as is then it can often be done with effort. The question is, are you up for the ongoing effort, and will you have miserable looking plants at points during every year?

What it usually takes to restore affected plants

We maintain a few gardens largely unaffected by either problem- largely in isolated spots in farmland, and here a single treatment for box blight when it appeared seemed to solve the problem for some years. We pruned out diseased parts really hard, rigorously removing clippings from site and used chemical controls as well (see the RHS advice in the above links).

There are also chemical and biological controls for the box caterpillar, and some clever early warning systems (catch the moths as they arrive and this tells you when to treat the plant for the caterpillars that will follow).

Obviously the worse the infection/infestation, the less likely the plants are to recover and you will need to put in place good ongoing control methods -this will not be a one-off!

As a result, unless the specimens are particularly good and important, or you are managing to keep it under control at present, our advice most often is to replace the box with something that is not susceptible to these problems. Whilst there will be a cost to this, it is in most cases a huge relief to remove miserable looking specimens and replace them with something lovely again, whilst also removing the ongoing effort of trying to keep a sinking ship afloat!

If you do have a few gorgeous specimens that you want to keep, minimising the rest of the box elsewhere may help you to focus efforts on the good stuff, and will reduce the liklihood of disease spreading from one to the other.

We have put together suggestions on box replacements as well as our take on why this can be a good thing HERE. We are happy to provide advice and suggestions that will suit you particular garden if you have decided to give up the fight!

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