Pest of the Month: Leek Moth

If you find that one of your leeks is not growing as quickly as the others, then you will most likely find that there is a leek moth caterpillar living on the plant…

Leek Moths lay their eggs in May/June, and again in August/September. They are attracted to plants from the allium family, particularly (as their name suggests) leeks, laying their eggs in the foliage. When they hatch, the caterpillars will start to feed on the leek leaves, more often than not eating the newer, younger leaves from the centre of the plant, and thus preventing the leek from growing. They’ll also nibble into the older leaves and stem, and occasionally even the roots.

You’ll most likely be aware of the problem when you realise that one or two of your leeks seems stunted. Once the damage is done, there’s not much hope for recovery, but you should try to protect the rest of your crop. First, check the other plants for eggs or baby caterpillars (look down in the centre of the leaves) and remove any that you see. Then, it is wise to pop some fleece over the crop to protect them from future moths.