Troubleshooting
Dipladenia (Mandevilla) problems — and how to fix them
Dipladenia (Mandevilla) (Mandevilla spp.) 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.
No flowers
Too little light (under 6 hours of sun), spring temperatures below ~18°C/65°F, or a high-nitrogen feed that favours foliage over blooms.
Bud drop
Sudden swings in temperature, light or watering, or a spell of drought stress that makes the plant shed buds before they open.
Yellowing lower leaves
Usually overwatering or cold, wet roots, especially when watering is not reduced over winter.
Red spider mite
Hot, dry indoor air encourages mites, causing fine speckling and bleaching of the leaves and faint webbing.
Mealybugs and whitefly
Sap-sucking pests that thrive under glass, leaving sticky honeydew and sooty mould on leaves.
Aphids on new growth
Soft tips and flower buds attract aphids that distort growth; rinse off and treat with horticultural soap.
Prevent dipladenia (mandevilla) problems before they start
Most dipladenia (mandevilla) issues are care-mismatch, not bad luck. Dial in the basics:
Dipladenia (Mandevilla) problems — FAQ
Why is my dipladenia (mandevilla) no flowers?
Too little light (under 6 hours of sun), spring temperatures below ~18°C/65°F, or a high-nitrogen feed that favours foliage over blooms.
Why is my dipladenia (mandevilla) bud drop?
Sudden swings in temperature, light or watering, or a spell of drought stress that makes the plant shed buds before they open.
Why is my dipladenia (mandevilla) yellowing lower leaves?
Usually overwatering or cold, wet roots, especially when watering is not reduced over winter.
Why is my dipladenia (mandevilla) red spider mite?
Hot, dry indoor air encourages mites, causing fine speckling and bleaching of the leaves and faint webbing.
Why is my dipladenia (mandevilla) mealybugs and whitefly?
Sap-sucking pests that thrive under glass, leaving sticky honeydew and sooty mould on leaves.
Why is my dipladenia (mandevilla) aphids on new growth?
Soft tips and flower buds attract aphids that distort growth; rinse off and treat with horticultural soap.