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This is an urgent post (May 2021) to help you save your box plants and control the caterpillar before it’s too late. In this article, we look at How to Stop Caterpillars Eating Box Plants.

The Boxwood Tree Moth or more importantly the caterpillar is about to spend another year wreaking havoc on our Box plants and hedges, catch it early before it does!

For the last two years, my box plants have suffered from caterpillar damage, sometimes decimating plants in less than 36 hours. I foolishly thought I could control the problem by picking off the caterpillars every day. However, just as I thought I had got every caterpillar, I would find more excessive damage the next day.

Which comes first the Caterpillar or the Moth?

You would think the answer to which comes first, the caterpillar or the moth? Would be similar to the age-old question, which comes first the chicken or the egg? BUT we actually have the answer here!

In this case, the box eating caterpillar overwinters between box leaves, protecting itself in a web from the ravishes of the winter. This means the season’s cycle actually starts with the caterpillar!

which comes first caterpillar or moth

As the weather warms up the caterpillars emerge and start munching on the leaves. Building energy to metamorphose into moths, which go on to lay more eggs and so the cycle continues.

How to control the box eating caterpillar

First off, don’t do what I did and expect to control the caterpillar by picking them off the plant. This does reduce the population, however, as I said earlier, Just when you think you have the little blighters sorted, another attack has started to take place.

At the end of last season, I finally bit the bullet and bought a packet of XenTari Boxwood Caterpillar Control and, with great relief, saw an end to Buxus leaf damage.

This control is very simple to use and is a natural biological control that is safe for birds, bees and other wildlife.

It is expensive but the powder comes in 3 gram packets which are enough to treat 30 square metres of plants or hedging. So you could share the other packets with your gardening friends or groups… for a small donation, of course!

How to use Xentari Caterpillar Killer

One box of Xentari Caterpillar Control contains 5 sachets of powder (3 grams per sachet).

Always follow the instructions on the box but generally, pour 3 litres of water into a clean sprayer and then add one 3g sachet of Xentari powder to the water and mix by shaking the sprayer. Then simply spray your plants.

This mix will treat approximately 30 square metres of hedging or plants.

If you have a large area to spray, make up more solution, keeping the same 3 litres of water to 3 grams of powder ratio.

Do the Boxwood Moth Pheromone Traps work?

Boxwood Moth pheromone traps do work at certain times of the life cycle. For example, the traps will not catch any moths at the beginning of the season. This is because the caterpillar overwinters between plant leaves and then turns into the moth. It is likely that you will not see any moths until mid to late June. By this time the caterpillar will have already caused damage to the plant.

That said, breaking the life cycle of pests, is the key to reducing the damage, so catching the moths as soon as they emerge, can help reduce the chance of an infestation.

I have written a more in depth post on Buxus problems and solutions, you can find it here