What's eating my tree houseleek?

Tree Houseleek is grown indoors and outdoors in mild climates. Indoors, mealybugs and scale insects attack stems and rosette centres. Outdoors, aphids cluster on new growth and slugs may rasp young leaves. Vine weevil grubs are a real outdoor threat, eating the roots. Active growth is in cool, moist months — check plants then.

White waxy fluff in the centre of rosettes or at stem nodes; leaves yellow and rosettes may collapse. Dab colonies with a 70% isopropyl alcohol swab. For widespread infestations apply dilute neem oil spray, covering the rosette centre.

Clusters of small green or black insects on new growth in spring; distorted young leaves and sticky honeydew. Blast off with water; spray with insecticidal soap. Outdoors, encourage ladybirds and lacewings as natural predators.

Roots eaten by fat, creamy-white grubs; plant suddenly collapses and pulls easily from soil with no roots attached. Apply a pathogenic nematode drench (Steinernema kraussei) in late summer/autumn when soil is warm. Check soil when repotting.

Ragged holes or silvery slime trails on soft new leaves and rosettes, mainly outdoors or in damp conservatories. Remove by hand at night; use copper tape around pots; apply wildlife-safe iron phosphate pellets (UK: approved metaldehyde replacement).