How to Identify and Cure Box Tree Caterpillar (Boxwood)

Box tree caterpillars can eat their way through your box / boxwood plant in just one week, leaving your box plant brown, leafless and in poor health.

The troublesome box tree caterpillar (Cydalima perspectalis) was first confirmed munching garden box (Buxus) plants in the UK in 2011. Since then the box tree moth has rapidly spread across the country, leaving in its wake a trail of troubled topiary and hard-hit hedges.

I’ll show you four clear symptoms which you can use to identify box tree caterpillars on your box plants: eaten leaves with wispy leaf veins remaining, caterpillar poo or frass, silken webbing and then the caterpillars themselves - masters of disguise!

I also show you how to distinguish between box tree caterpillar infestation and the boxwood blight fungus.

Finally I show you the different methods you can use to control and treat the devastating box tree caterpillar. I summarise the pros and cons of insecticides, the benefits of biological pesticides based on Bacillus thuringiensis, the use of pheromone traps, nematodes, manual removal and natural predators.

Finally, if you want to ‘think outside the box’ I give some recommendations for box plant alternatives.

⌚ Timestamps

00:00 How to know if you have Box Tree Caterpillar
00:30 Key symptom 1: Eaten leaves
01:02 Key symptom 2: Caterpillar frass or poo
01:20 Key symptom 3: Silken webbing
01:35 Key symptom 4: Box tree caterpillars themselves
02:24 Box tree caterpillar infestation or boxwood blight?
02:40 Insecticides and biological pesticides
03:24 Pheromone traps
03:42 Nematodes
04:04 Manual removal and natural predators
04:30 Is there a magical solution?
04:51 Box plant alternatives

📸 Map images courtesy of NBN Atlas

Please note: Thoughts shared in this video are my personal opinions. I'm not paid any money to promote the gardening products I talk about or use here.

Wishing you healthy plants, and happy gardening! 🌸