What's eating my calendula?

Calendula is a magnet for aphids outdoors, which colonize soft stems and flower buds fast. Thrips, powdery mildew (a fungal issue), slugs, and earwigs also attack. Because calendula is commonly used as a companion plant to lure aphids away from vegetables, heavy aphid pressure is almost guaranteed.

Dense colonies on stems and under leaves; sticky honeydew, sooty mold, and distorted buds that fail to open properly. Knock off with a strong jet of water; apply insecticidal soap or neem oil. Encourage aphid predators such as ladybirds and parasitic wasps.

Silver or brown scarring and streaking on petals and leaves, distorted flowers, and tiny dark frass specks on white paper held below the plant. Remove infested blooms; introduce Amblyseius predatory mites; spray with spinosad or insecticidal soap, targeting the growing tips.

Ragged holes in leaves and seedlings, especially near soil level after rain or overnight; characteristic silvery slime trails. Apply iron phosphate slug pellets; set beer traps; remove debris where slugs hide and hand-collect after dark.

Irregular, jagged holes in petals and leaves, often blamed on slugs but earwigs leave cleaner-edged cuts; mostly active at night. Trap under rolled damp newspaper or a flowerpot filled with straw; empty traps each morning. Diatomaceous earth around the base also helps.