What's eating my mint?

Mint is a vigorous herb but is heavily targeted by aphids and spider mites, which colonise tender new growth. Mint flea beetles create tiny shot-holes in leaves. Slugs attack young plants. In the UK, mint leaf beetle (Chrysolina herbacea) can defoliate plants. Caterpillars of the mint moth also skeletonise leaves. Good drainage and thinning reduce pressure.

Clusters of small green aphids on shoot tips and undersides; sticky honeydew; curled, distorted new leaves; growth stalls. Blast off with a strong water spray; apply insecticidal soap; encourage aphid predators such as ladybirds and hoverflies; cut stems hard to remove colonies.

Metallic green-blue beetles and their dark grubs chew large irregular holes in leaves; severe infestations can completely defoliate a plant. Pick off beetles and larvae by hand (they drop when disturbed — hold a container underneath); apply pyrethrin as a last resort on non-harvest days.

Fine pale stippling across leaves; bronze or silvery look to foliage; webs under leaves in dry spells; common on container-grown mint indoors. Increase watering frequency and mist foliage; apply neem oil or insecticidal soap spray; for outdoor plants, a hard cut-back and new growth usually recovers quickly.

Ragged holes in young leaves and stems; silver slime trails; worst on newly planted or pot-grown mint in damp conditions. Apply iron phosphate pellets around the base; use copper tape on containers; water in the morning so foliage and soil surface dry by evening.