It’s no surprise that topiary balls and cones made using box (Buxus) are so popular these days. Such cleverly trimmed shapes add elegant formality to any garden – large or small, rural or inner-city. Plus box is an evergreen. That means year round interest, something we’re all desperate for during the winter months. But, sadly, lots of people who have box also now have box blight! Indeed it seems to be massively on the rise. So today I’m going to cover off the treatment for box blight.
If you’re thinking box blight is the very reason I don’t have box, please do still read on. At the end of this blog I’ve an exciting new plant to share with you. It works like box – but doesn’t get blight, and it has blooms!
What is Box Blight
Before I turn to the treatment for box blight, I ought to first off cover what it is and how to spot it. Not least because there’s another kind of problem called Volutella blight which isn’t so bad, and is easier to control, so you don’t want to mix them up.
Box blight’s formal name is Cylindrocladium buxicola and it’s a fungal disease. Apparently it first appeared in Britain in 1998 but it seems to me that it has taken a much firmer hold recently. I wonder if this could be caused by our changes in weather as it likes warm, humid conditions.
Box blight causes the tiny leaves of box to go brown and the stems dieback. You end up with pale browny-yellow bare patches. As you can imagine this can look dreadful – really wrecking the look of the plant.
While box blight doesn’t kill the roots, all that leaf damage understandably takes its toll on the plant – and it’s quick to spread. So you really need to know how to spot it early on.
How To Spot It
To make life, and the treatment for box blight, very complicated, it’s not just volutella blight that it might be confused with. The damage caused by the box tree caterpillar can look similar too. So I’ve created a handy table of symptoms to help us!
| Box Blight | Volutella | Caterpillar |
|---|---|---|
| Leaves turn brown and fall | Leaf damage same as box blight | Leaf damage but the leaves are being eaten |
| Black streaks | No black streaks | No black streaks |
| Young stems dying | Young stems dying like box blight | Young stems dying like box blight |
| White spores on the underside of infected leaves | Pink spores | White webbing Caterpillars Pale yellow flake-like droppings Pale yellow eggs on underside of leaves |
Treatment for Box Blight
OK, so you’ve looked at the table and yes, you’ve box blight. What now? Well, there are a couple of ways to treat it, but which ever you go for the trick is to act fast. If it fully takes hold of your plant it’s really terrible to treat and will involve a lot of effort.
Option 1 – Cutting out
The least drastic option is as soon as you spot the signs of box blight, cut out the affected area, plus I’d take a out a generous portion beyond it as the infection has probably spread further than you can see. Use good sharp, hand tools, not power tools, as they crush the leaves, making them more vulnerable to infection.
Whatever kit you use, clean the it well with disinfectant afterwards. Also clean your shoes and hands. As the last thing you want to do is personally spread the spores around your garden!
As box blight is a fungal infection, it likes damp conditions. So you want to do the cutting back when the weather is dry. Otherwise you will dislodge the fungal spores and they will spread further!
Put a plastic sheet down when you cut – this will make it easier to collect up all the infected leaves when they fall.
Dispose of all the cuttings – do NOT put any on your compost heap!
What about Fungicides?
There are fungicides you can put on your box plant during this method to prevent the spread. You apply these before and after cutting out the affected areas. But personally, I don’t like adding any chemicals to my garden. I’d rather lose the box than start using sprays. But that’s just me – you do what you feel is best for your garden.
Option 2 – Cutting back
If you try option 1 and you still have a problem you may need to be more drastic. To be honest if option 1 doesn’t work I probably jump straight to option 3 which is get rid of the affected plants all together! But if you’re more patient than me and your infected plant is a box hedge, you could try cutting it back. (Obviously not an option for topiary shapes) This is no time for half measures I’m afraid. You need to make a significant cut back to the hedge both in terms of its height and width. By at least a third if not a half.
After cutting them back, give the box plants a good water (at the base not on the leaves) and feed with a general purpose fertiliser.
Cutting back like this does two things. It removes the affected areas but it also gives the healthy part of the plants more light and air which will help them bounce back.
Again during the cutting back you must follow the hygiene advice of option 1 (put down sheeting, chuck everything away, nice sharp tools, and disinfect afterwards). I can sense you groaning as I list all these things. Perhaps you can now see why I jump straight to option 3 and stick the blooming blighter in the bin!!
Box Blight Prevention
Obviously it’s better to prevent box blight all together than to have to treat it. And the good news is there are simple steps you can take to inhibit it in your garden.
Ten Steps to Blight-free Box
- Check plants regularly (caught early it is sooooo much easier to deal with)
- Spores if they’re there, will spread when you trim. So trim only once a year
- Do this in dry breezy weather
- Trim early in the season. You don’t want to be in a position where the leaves haven’t a chance to heal before frost arrives. That’s because blight spores can more easily enter in frosty conditions
- Use sharp hand tools and disinfect your tools afterwards
- Don’t plant your box in dark, damp spots
- Ensure there’s good air circulation around your plants
- Feed regularly during the growing season (a fed, healthy plant is more resitant to all diseases)
- When watering, focus the water on the base of the plant, you don’t want wet leaves
Bloombux – A New Alternative to Box
If your treatment for box blight fails and you have to get rid of your plant – or you have never bought box as you don’t want to risk all those pesky caterpillars and box blight – I have a treat for you!
I’ve just been introduced to Bloombux – a real alternative to boxwood.
It can be pruned just like a box, but Bloombux doesn’t get the diseases and problems which can blight it. Added to this, while it is an evergreen like box, Bloombux is much showier. It produces lovely flowers from May onwards and through June. These are only available in a pale pink or stronger magenta. But if these fit your colour scheme, I’d take a serious look.
Although it’s like a box (with loads of flowery bonuses), Bloombux is actually a dwarf rhododendron. To be precise, it’s a cross between two wild species – hirsutum and micranthum. But before you groan ‘Rhododendrons! But my soil isn’t acidic!’ relax…it doesn’t need particularly acid soil. It’s wonderfully uncomplicated. It will grow in almost any loose garden soil in a sunny to semi-shady location and can be planted all year round.
I love an easy-peasy plant like this, but I like the look of its versatility too. You can group it in a bed, have it as a feature plant in a container, or use it as an edge for a border (see above). With a growth height of between 70 and 100 cm, it would be ok used as a small hedge too.
I like the look of it for a container on a patio. It creates a pleasing ball shape. Though the experts say, if you are keeping it in a pot, choose one slightly larger than you would normally, as Bloombux plant has a large root ball.
So there you have it. The best way to treat box blight – plus a new alternative plant for you to try. Hope you like this ‘out of the box’ thinking. (Sorry couldn’t resist!). Happy gardening – x
P.S.If you are thinking about box, and all things topiary, you may like this other blog of mine on the best topiary shapes to try
