What's eating my pelargonium 'lemon fancy'?

Pelargonium 'Lemon Fancy', a scented-leaf herb geranium, is most troubled by vine weevil grubs eating roots and aphids clustering on soft shoots. Outdoors, caterpillars and slugs can damage foliage. The strong lemon scent deters some pests but does not prevent all infestations.

Soft shoot tips curl and distort; sticky honeydew coats leaves with sooty mould following. Blast off with a strong water jet; apply insecticidal soap or neem oil spray; encourage ladybirds and lacewings.

Plants wilt suddenly despite adequate watering; C-shaped cream grubs found eating roots when plant is lifted. Apply Steinernema kraussei nematodes to moist compost in late summer; use vine weevil killer drench; check roots of repotted plants.

Leaves webbed together or with ragged holes; silken threads visible among foliage. Pick caterpillars off by hand; apply Bacillus thuringiensis (Bt) spray to foliage; remove webbed leaf bundles.