What's eating my horse mint?

Horse mint (Mentha longifolia) is a robust wild-type mint affected by the same specialist feeders as other mints: mint aphids cluster on shoot tips, mint flea beetles punch shot holes in leaves, and mint moth caterpillars roll and feed inside leaf folds. Spider mites can be problematic in dry exposed sites. Harvest frequently to keep plants clean.

Dense pale green colonies on growing tips; shoot tips curl and become sticky with honeydew; sooty mould may colonise residue Spray with insecticidal soap or neem oil; dislodge with water; cut back heavily infested stems to the base to promote clean regrowth

Shot-hole damage across upper leaf surfaces; tiny shiny beetles jump off when disturbed; leaves may look tattered and brown-edged Apply pyrethrin-based spray in the evening when bees are inactive; use row covers; clear old stems in autumn

Leaf-rolling with silk threads; green caterpillars feeding within the roll; can affect multiple growing tips Hand-pick rolled leaves and destroy; apply Bt spray at first sign of leaf rolling

Pale bronzed stippling and webbing on leaf undersides, most noticeable in warm dry conditions Mist foliage regularly; use neem oil spray on undersides; remove worst-affected shoots