Troubleshooting
Twinspur problems — and how to fix them
Twinspur (Diascia barberae) 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.
Summer dormancy / heat stress
Diascia barberae often goes dormant or stops flowering when temperatures consistently exceed 25°C. Cut back by half, reduce watering, and flowering typically resumes in cooler autumn weather.
Botrytis (grey mould)
In cool, damp conditions grey mould can rot stems and flowers. Remove affected material promptly, improve air circulation, and avoid wetting foliage when watering.
Slugs and snails
Young growth is attractive to slugs, particularly in mild, damp climates. Use copper tape around containers, encourage predators, or apply iron phosphate pellets around garden plants.
Prevent twinspur problems before they start
Most twinspur issues are care-mismatch, not bad luck. Dial in the basics:
Looking for twinspur in general rather than its problems? Read the full twinspur care guide — light, water, soil and feeding.
Twinspur problems — FAQ
Why is my twinspur summer dormancy / heat stress?
Diascia barberae often goes dormant or stops flowering when temperatures consistently exceed 25°C. Cut back by half, reduce watering, and flowering typically resumes in cooler autumn weather.
Why is my twinspur botrytis (grey mould)?
In cool, damp conditions grey mould can rot stems and flowers. Remove affected material promptly, improve air circulation, and avoid wetting foliage when watering.
Why is my twinspur slugs and snails?
Young growth is attractive to slugs, particularly in mild, damp climates. Use copper tape around containers, encourage predators, or apply iron phosphate pellets around garden plants.