How to Treat Box Blight

There is currently no fool-proof silver bullet available to either professional growers or amateur gardeners in the UK that will either prevent or eradicate Box Blight.

However, the RHS does list a few options that MIGHT help. These include branded fungicides containing myclobutanil, tebuconazole and/or triticonazole. The RHS, though, makes it absolutely clear that their use against Box Blight is unproven and at the user’s risk – and their own research has shown myclobutanil to be ineffective at controlling Cylindrocladium Blight.

But, as I write this, we can be confident that every manufacturer of horticultural fungicides is trying to develop an effective treatment – be it a preventative or curative solution.


Well, at the risk of appearing cynical, that solution will be worth a fortune. And there are encouraging signs from the Continent – Belgium to be precise. There, commercial Box grower, Karel Goossens, has successfully treated several important Box gardens with chlorothalonil – a fungicidal spray. It is an intensive process requiring repeated treatments (five per year), each achieving 100% coverage. Chlorothalonil is not (yet) available in the UK, but it appears to work and offers hope for the future.

But is Box Blight fatal?

This is perhaps the most controversial and divisive aspect of Box Blight – if you have it, do you HAVE to rip up the plants and burn them?

Let’s get right to the point – the answer is NO.

Box Blight can kill a plant, but this is by no means inevitable and while infected stems must be cut out and burned, the main reason that total removal is often recommended is aesthetic – a post-surgery Box is not the prettiest sight and that is why (along with Box’s affordability) those responsible for major gardens open to the public are often dealing with Box Blight in the most drastic way possible. Frankly, if the affected plant is of no particular size or importance, then rip it up. But if it is a long-established friend and Blight has yet to spread beyond a few stems, then it is worth a more remedial approach.

Take a leaf, so-to-speak, out of Mary Payne MBE’s book…This well-respected and highly experienced Somerset-based horticulturalist has demonstrated that Box Blight is not inherently fatal. One of her clients had infected plants. She cut out all the diseased wood back to healthy growth (this is the first thing to do if you discover Box Blight), removed all the diseased foliage (using a garden vacuum cleaner – a good tip) and replanted them in a more open site. The Box Blight has not returned. Other famous gardeners also recommend this more cautious approach – including Bunny Guinness who has changed her opinion: “…I’ve revised my ideas and I would not advise pulling infected plants out.”

Please remember, though, that while diseased foliage should be cut back to healthy wood, healthy foliage MUST be left completely and utterly untouched and untrimmed – cut stems simply make it easier for Box Blight to spread. Living with a scruffy Box is a small price to pay for having the chance of keeping it.

If you’re concerned about Box Blight and would like further guidance on preventing it, feel free to contact Hedge Xpress on 01993 850979. We would be more than happy to help guide and assist you in any way we can.