What's eating my impatiens?

Impatiens are highly vulnerable to two-spotted spider mites in hot, dry conditions, causing rapid bronzing of foliage. Aphids cluster on new growth and thrips streak petals. Fungus gnats breed in consistently moist potting mix when grown in containers. Impatiens downy mildew (Plasmopara obducta) can devastate entire plantings and is often confused with pest damage — scout carefully.

Fine pale stippling on upper leaf surfaces; webbing underneath; leaves yellow and drop in severe infestations; worst in heat and drought. Increase watering and humidity; remove and bin heavily infested stems. Apply neem oil or insecticidal soap to undersides of leaves, repeat weekly.

Soft sticky colonies on shoot tips and flower buds, causing distorted new growth and promoting sooty mould. Blast off with water; apply insecticidal soap. Encourage beneficial insects. Repeat treatments as populations rebound quickly.

Silver-white streaking on petals; brown scarring on buds; leaves may show tiny specks with dark frass dots. Remove damaged flowers; apply spinosad or insecticidal soap, targeting buds and leaf undersides. Blue sticky traps help monitor levels.

Adults are a minor annoyance; larvae in potting soil eat fine roots, causing wilting and yellowing in potted impatiens. Allow the top inch of soil to dry between waterings. Apply beneficial nematodes (Steinernema feltiae) or Bacillus thuringiensis israelensis (Bti) drench to soil.