Troubleshooting
Penstemon 'Stapleford Gem' problems — and how to fix them
Penstemon 'Stapleford Gem' (Penstemon 'Stapleford Gem') 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.
Winter losses in wet soil
Soggy, cold ground over winter rots the crown. Plant in sharp-draining soil and consider a gravel mulch; take autumn cuttings as insurance.
Powdery mildew
White coating on leaves in humid, crowded conditions. Improve airflow, avoid overhead watering, and remove affected growth.
Floppy, sparse flowering
Caused by too much shade or over-rich soil. Move to full sun and ease off nitrogen feeds for stronger, more upright spikes.
Short-lived clumps
Penstemons tend to decline after a few years; refresh stock regularly from cuttings to keep the display vigorous.
Prevent penstemon 'stapleford gem' problems before they start
Most penstemon 'stapleford gem' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for penstemon 'stapleford gem' in general rather than its problems? Read the full penstemon 'stapleford gem' care guide — light, water, soil and feeding.
Penstemon 'Stapleford Gem' problems — FAQ
Why is my penstemon 'stapleford gem' winter losses in wet soil?
Soggy, cold ground over winter rots the crown. Plant in sharp-draining soil and consider a gravel mulch; take autumn cuttings as insurance.
Why is my penstemon 'stapleford gem' powdery mildew?
White coating on leaves in humid, crowded conditions. Improve airflow, avoid overhead watering, and remove affected growth.
Why is my penstemon 'stapleford gem' floppy, sparse flowering?
Caused by too much shade or over-rich soil. Move to full sun and ease off nitrogen feeds for stronger, more upright spikes.
Why is my penstemon 'stapleford gem' short-lived clumps?
Penstemons tend to decline after a few years; refresh stock regularly from cuttings to keep the display vigorous.