Box hedge issue - what is it?

nedwards0267066 · 20 January

Hi everyone

I’d be very grateful for any advice on this box hedge which is about 15 years old, maybe more.

Patches of the hedge seem to be turning brown / dying. I discovered this early last year and trimming it recently brought more to light. See attached photo.

Worried it will continue to spread and the whole hedge will die! Can’t see any evidence of caterpillars so not sure what it could be.

All ideas / advice welcome. Thank you!

Allotment Boy · 20 January

Any caterpillars will be pupating in the ground at this time of year. Most Box is suffering the double hit of blight and the Box moth. If you don't want to use chemicals there is not much you can do about the moth except trap it and hope to reduce the damage that way. As for blight the only real defence is growing strong healthy plants, some say that the product Top box helps, sometimes foliar treatment with seaweed TONIC not feed can help toughen up leaves so they can resist it. Many gardens and gardeners have given up on box and are looking to alternative plants.
Sorry to be gloomy but that's the reality.

AnniD · 20 January

My money is on box hedge caterpillars. Sometimes you can't see the damage until it's too late, and as @Allotment Boy says, there will be no obvious signs at this time of year of either the caterpillars or the moths.
I have sadly had to get rid of the majority of my box plants as have many others on this forum. There are various treatments you can try, but it depends on how much effort you're willing to put in, and it won't be a one off treatment either l'm afraid.

There are several threads about the problem, here is one.
https://forum.gardenersworld.com/discussion/1059170/is-this-box-blight/p1

ViewAhead · 20 January

I have to say, I agree. That looks like classic moth caterpillar damage. I have lost my 20+ yr old specimens over a period of 4 yrs or so. 😕 Those bare patches in the photo will try to green up in spring. If you can be really vigilant and check for caterpillars daily from April to Sept, you may stave off complete disaster, though the pesky blighters do try hiding in the depths to escape notice as they carry out their deadly defoliation.

nedwards0267066 · 20 January

Thank you everyone for taking the time to answer. What a shame

I’ll have a read through the other thread for possible treatment options.

Reading through one now; the moth issue seems to have come on so suddenly!

Dovefromabove · 21 January

We found several of the moths in our garden this year … I’d never seen them here before … thankfully we don’t have any box … but there are lots of lovely gardens that do. 😞

AnniD · 21 January

There are various articles online giving advice on how to deal with it, including this one which l've just picked at random and seems pretty comprehensive.
https://www.gardensillustrated.com/garden-advice/how-to/box-caterpillar-what-how-to-treat

The advice about picking off the caterpillars made me smile based on my personal experience. My OH and l thought we'd removed as many as we could before digging out the plants. When l began to cut the plants up, l was finding them hiding all over the place, and it's no exaggeration to say the numbers were in the early hundreds by the time l had finished.
I tried putting a few on the bird tables but there was no interest. I have seen sparrows and magpies pecking at the small front hedge that we still have, but they aren't all that interested, and l think it would be a 24/7 job for any spuggie to keep the numbers down.

Where my Dad lives, a neighbour had a beautiful box hedge. It has now been absolutely destroyed by the caterpillars and is a sad sight.

ViewAhead · 21 January

Re the picking off, you do have to start immediately the problem appears. At first, the caterpillars seem to graze on the outer foliage, and then they work their way deeper, in my experience. That said, I couldn't hold off decimation for more than a couple of seasons. As a cheap first line of defence though, it is not a bad tactic. 🙂

The hedge in the photo looks like the damaged areas are relatively small at the moment, so worth a try, IMV.

bédé · 21 January

Keep a sharp look-out as soon as the weather starts to warm. Pulling complete stems through your fingers seems to be the easiest way to remove tiny ones.

thevictorian · 21 January

The box moths turned up here in norwich a few years ago and we began to see patches like those in all the box locally. Since then the problem has got much worse and whilst small hedges succumbed in the first year, 2 years later all the massive hedges have completely been killed as well. I don't know of any box locally that hasn't been effected and the moths are continuing north. We see more adult moths as well and despite being beautiful, I don't think that bodes well the spreading of this plague.

I don't grow box but I wouldn't even contemplate it now either and choose an alternative instead.

Topbird · 21 January

I dug out one of the box hedges a couple of years ago. It was often affected by blight and then the moths / caterpillars moved in and it was just a sad and sorry mess.

However, I did keep some box unaffected box including 5 large box balls. They were chewed by the caterpillar for the first time last year. I also actually saw the moths for the first time last summer. All this suggests to me that the problem is getting much worse and spreading fast.

Box hedge issue - what is it?

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