What's eating my field marigold?

Field marigold (Calendula arvensis) is most troubled by aphids, particularly black bean aphid and greenfly, on soft stems and flower buds. Powdery mildew weakens late-season plants, and slugs eat seedlings and young foliage. Despite the reputation of garden marigolds as pest-deterrents, Calendula itself does attract aphids.

Dense colonies on stem tips and around flower buds; sooty mould and distorted new growth. Spray with insecticidal soap or diluted neem oil; encourage ladybugs and lacewings; remove heavily infested shoots.

Seedlings and soft young stems eaten at soil level; holes in lower leaves. Use iron phosphate pellets; mulch with grit; sow seed in modular trays and transplant at a larger size.

Irregular holes eaten in leaves; flower petals chewed; larvae sometimes found inside buds. Hand-pick eggs and caterpillars; apply Bt spray for larger infestations on ornamental plantings.