What's eating my pelargonium crispum?

Pelargonium crispum (lemon-scented geranium) is commonly attacked by aphids, whitefly, and vine weevil outdoors, and by spider mites when kept indoors in dry conditions. Botrytis grey mould can also damage stems in cool, damp weather. Aphids on soft new growth are the most frequent complaint.

Dense colonies on tender shoot tips; sticky honeydew, distorted leaves, and possible sooty mould. Squash by hand or use a water jet; treat with insecticidal soap or neem oil; introduce biological controls such as Aphidius wasps under glass.

White powdery adults flutter from foliage; yellowing, sticky leaves with sooty mould below. Yellow sticky traps; spray with pyrethrin or insecticidal soap in the evening; repeat weekly for 3–4 weeks.

Irregular scalloped notches on leaf edges (adult); pot plants suddenly collapse as larvae devour roots. Apply pathogenic nematode drench in late summer/early autumn; inspect root ball when repotting and remove cream c-shaped grubs.