Troubleshooting
Mandevilla 'Alice du Pont' problems — and how to fix them
Mandevilla 'Alice du Pont' (Mandevilla x amabilis 'Alice du Pont') 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.
Poor flowering
Too little light or over-feeding with nitrogen produces foliage but few blooms. Give full sun, feed with a high-potash fertiliser, and ensure warm conditions for the flush to continue.
Cold damage
Frost-tender; suffers below about 10°C and is killed by frost. Bring containers indoors before autumn cold and overwinter frost-free, cutting back hard if needed.
Spider mites and whitefly
Common indoors and in dry heat; mites stipple leaves with fine webbing, whitefly cluster underneath. Raise humidity, inspect leaf undersides and treat with insecticidal soap or oil.
Yellowing leaves / root rot
Overwatering or poor drainage yellows leaves and rots roots. Use a free-draining mix, let the surface dry between waterings, and never leave the pot standing in water.
Prevent mandevilla 'alice du pont' problems before they start
Most mandevilla 'alice du pont' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for mandevilla 'alice du pont' in general rather than its problems? Read the full mandevilla 'alice du pont' care guide — light, water, soil and feeding.
Mandevilla 'Alice du Pont' problems — FAQ
Why is my mandevilla 'alice du pont' poor flowering?
Too little light or over-feeding with nitrogen produces foliage but few blooms. Give full sun, feed with a high-potash fertiliser, and ensure warm conditions for the flush to continue.
Why is my mandevilla 'alice du pont' cold damage?
Frost-tender; suffers below about 10°C and is killed by frost. Bring containers indoors before autumn cold and overwinter frost-free, cutting back hard if needed.
Why is my mandevilla 'alice du pont' spider mites and whitefly?
Common indoors and in dry heat; mites stipple leaves with fine webbing, whitefly cluster underneath. Raise humidity, inspect leaf undersides and treat with insecticidal soap or oil.
Why is my mandevilla 'alice du pont' yellowing leaves / root rot?
Overwatering or poor drainage yellows leaves and rots roots. Use a free-draining mix, let the surface dry between waterings, and never leave the pot standing in water.