Troubleshooting
Stiff twinspur problems — and how to fix them
Stiff twinspur (Diascia rigescens) 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.
Mid-summer flowering pause
Like other Diascia species, D. rigescens may pause blooming in peak summer heat above 25°C. Cut flowering stems back by one-third to one-half to encourage a strong late-summer/autumn flush.
Botrytis on dense spikes
The tightly packed flower spikes can trap moisture, fostering grey mould in wet weather. Remove spent flower heads, improve air circulation, and avoid overhead irrigation.
Short-lived in heavy soil
In poorly drained or clay-heavy garden soil, plants often decline within one or two seasons. Improve drainage with grit or grow in raised beds to extend plant longevity.
Prevent stiff twinspur problems before they start
Most stiff twinspur issues are care-mismatch, not bad luck. Dial in the basics:
Looking for stiff twinspur in general rather than its problems? Read the full stiff twinspur care guide — light, water, soil and feeding.
Stiff twinspur problems — FAQ
Why is my stiff twinspur mid-summer flowering pause?
Like other Diascia species, D. rigescens may pause blooming in peak summer heat above 25°C. Cut flowering stems back by one-third to one-half to encourage a strong late-summer/autumn flush.
Why is my stiff twinspur botrytis on dense spikes?
The tightly packed flower spikes can trap moisture, fostering grey mould in wet weather. Remove spent flower heads, improve air circulation, and avoid overhead irrigation.
Why is my stiff twinspur short-lived in heavy soil?
In poorly drained or clay-heavy garden soil, plants often decline within one or two seasons. Improve drainage with grit or grow in raised beds to extend plant longevity.