Troubleshooting
Garden Phlox 'David' problems — and how to fix them
Garden Phlox 'David' (Phlox paniculata 'David') 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.
Powdery mildew
'David' is highly mildew-resistant but not immune; ensure good airflow, divide congested clumps and avoid wetting the foliage.
Spider mites
Stippled, bronzed leaves in hot, dry weather; keep plants watered and rinse foliage, treating with insecticidal soap if needed.
Floppy stems
In too much shade or rich soil stems stretch and flop; grow in full sun and thin weak stems in spring for self-support.
Reverted seedlings
Self-sown seedlings rarely come true and often revert to magenta; deadhead spent panicles to prevent seeding-out of the white form.
Prevent garden phlox 'david' problems before they start
Most garden phlox 'david' issues are care-mismatch, not bad luck. Dial in the basics:
- Common garden phlox problems — the species this cultivar belongs to
- Common garden phlox 'david' problems — our other guide for the same plant
- What's wrong with my plant? — the diagnosis apps compared
- Garden Phlox 'David' watering schedule
- Garden Phlox 'David' light requirements
- Best soil mix for garden phlox 'david'
- Garden Phlox 'David' temperature & humidity
- Full garden phlox 'david' care guide
Looking for garden phlox 'david' in general rather than its problems? Read the full garden phlox 'david' care guide — light, water, soil and feeding.
Garden Phlox 'David' problems — FAQ
Why is my garden phlox 'david' powdery mildew?
'David' is highly mildew-resistant but not immune; ensure good airflow, divide congested clumps and avoid wetting the foliage.
Why is my garden phlox 'david' spider mites?
Stippled, bronzed leaves in hot, dry weather; keep plants watered and rinse foliage, treating with insecticidal soap if needed.
Why is my garden phlox 'david' floppy stems?
In too much shade or rich soil stems stretch and flop; grow in full sun and thin weak stems in spring for self-support.
Why is my garden phlox 'david' reverted seedlings?
Self-sown seedlings rarely come true and often revert to magenta; deadhead spent panicles to prevent seeding-out of the white form.