Troubleshooting
Cape Leadwort (Blue Plumbago) problems — and how to fix them
Cape Leadwort (Blue Plumbago) (Plumbago auriculata) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Skin irritation when handling (plumbagin)
Sap, leaves, stems and roots contain plumbagin and can cause redness, blistering and contact dermatitis. RHS advises wearing gloves and protective clothing when pruning or repotting.
Few or no flowers
Almost always too little light — move to full sun. Avoid pruning in summer: blooms form on new growth, so cutting then removes that season's flower buds.
Pruned at the wrong time
Hard-prune in late winter or early spring before new growth, not in summer. A late-winter cutback keeps this fast, sprawling shrub compact and flowering well; light tidying through the year keeps it in bounds.
Sap-sucking pests indoors
Whiteflies, spider mites and mealybugs are the main pests, especially on plants grown indoors or under glass. Watch for yellowing leaves, webbing and sticky honeydew; treat with insecticidal soap or horticultural/neem oil.
Frost damage
Frost-tender (RHS H2). Penetrating cold kills top growth and can kill the plant; in zones below 8-9 grow in a pot and overwinter under glass or indoors. Established plants often regrow from the base after light frost.
Root rot / yellowing from overwatering
Sits unhappily in soggy soil and rots easily. Use free-draining soil, let the surface dry between waterings, and cut back water in winter dormancy.
Prevent cape leadwort (blue plumbago) problems before they start
Most cape leadwort (blue plumbago) issues are care-mismatch, not bad luck. Dial in the basics:
Cape Leadwort (Blue Plumbago) problems — FAQ
Why is my cape leadwort (blue plumbago) skin irritation when handling (plumbagin)?
Sap, leaves, stems and roots contain plumbagin and can cause redness, blistering and contact dermatitis. RHS advises wearing gloves and protective clothing when pruning or repotting.
Why is my cape leadwort (blue plumbago) few or no flowers?
Almost always too little light — move to full sun. Avoid pruning in summer: blooms form on new growth, so cutting then removes that season's flower buds.
Why is my cape leadwort (blue plumbago) pruned at the wrong time?
Hard-prune in late winter or early spring before new growth, not in summer. A late-winter cutback keeps this fast, sprawling shrub compact and flowering well; light tidying through the year keeps it in bounds.
Why is my cape leadwort (blue plumbago) sap-sucking pests indoors?
Whiteflies, spider mites and mealybugs are the main pests, especially on plants grown indoors or under glass. Watch for yellowing leaves, webbing and sticky honeydew; treat with insecticidal soap or horticultural/neem oil.
Why is my cape leadwort (blue plumbago) frost damage?
Frost-tender (RHS H2). Penetrating cold kills top growth and can kill the plant; in zones below 8-9 grow in a pot and overwinter under glass or indoors. Established plants often regrow from the base after light frost.
Why is my cape leadwort (blue plumbago) root rot / yellowing from overwatering?
Sits unhappily in soggy soil and rots easily. Use free-draining soil, let the surface dry between waterings, and cut back water in winter dormancy.