What's eating my sensation mixed cosmos?

Sensation Mixed cosmos (Cosmos bipinnatus) is generally pest-resistant but aphids colonise shoot tips and flower stalks. Thrips rasp petals, causing silvery streaks and distorted blooms. Slugs and snails attack seedlings and young plants. In deer country, cosmos flowers and foliage are readily browsed — fencing or repellents are needed.

Green or black colonies on tender shoot tips and underside of leaves; sticky honeydew and curling foliage. Knock off with water; apply insecticidal soap; plant with companion flowers to attract aphid predators.

Silvery streaking and stippling on petals; flowers fail to open fully or become distorted. Remove severely affected blooms; spray with insecticidal soap or spinosad; avoid excessive nitrogen fertiliser.

Seedlings and young plants eaten at soil level; slime trails left on foliage. Protect seedlings with copper tape or fine grit; apply iron phosphate pellets; sow under cover and transplant when larger.

Stems and flower heads browsed off, especially on plants at the border of gardens adjoining open land. Use deer repellent sprays; install deer fencing; plant in raised beds or pots on terraces if deer pressure is high.