If you have any box plants in your garden and  don’t already know about the box moth and caterpillar this one is for you. Read carefully or you  may find yourself with a skeletal bush writhing with fat green caterpillars.


This is what the new and dramatic threat to box trees look like:


and the parent mothboxtreecaterpillaradult-moth

This is what the RHS has to say about it:

What is box tree caterpillar?

Box tree caterpillars are the larvae of a moth that feeds on box (Buxus) plants. It is native to East Asia and it became established in Europe in 2007. Although adult moths were first found in the UK in light traps in 2008, it was not until 2011 that larvae were reported in private gardens in the home counties. By the end of 2014 the moth had become established in parts of London and surrounding counties; in many cases the caterpillars had caused severe defoliation indicating that the moth is likely to become a serious problem.

Quick facts

Common name Box tree caterpillar
Scientific name Cydalima perspectalis
Plants affected Box (Buxus)
Main symptoms Foliage is eaten and covered in webbing
Most active April-October

I have my friend Linda to thank for alerting me to the problem – I had designed a new garden for her in the spring, so it was with some concern that she noticed patches of brown appear on the box topiary – could it be the dreaded box blight? A closer inspection revealed this sort of thing tucked away:


a pupa nestled in a strong sac of webbing – and this


newly hatched pupae with excrement and wedding. Yuck.

The problem is spreading so we need to spread the word too. The RHS are asking all gardeners to report the problem to them so they can track it.


So far we’ve got the worst of it BUT the good news is that it’s treatable. Ask your garden centre to recommend a spray such as Bug Clear or Provado and make sure you work through the plant in a thorough and meticulous manner. The spray will only give protection for two weeks or so – so vigilance is the word. It seems there is one more job to add to the list of garden chores – watch out for these blighters.