Troubleshooting
Arp Rosemary problems — and how to fix them
Arp Rosemary (Salvia rosmarinus 'Arp') 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 wet, not just cold
Even this hardy cultivar dies in cold, waterlogged soil; sharp drainage matters as much as low temperatures for getting it through winter.
Powdery mildew
Dense foliage in damp, still air develops white mildew; provide good airflow, avoid wetting the leaves, and don't overcrowd.
Bare, woody base
Old plants go leggy and woody low down; trim lightly after flowering and never cut back into leafless old wood, which seldom reshoots.
Root rot in containers
Pots that stay soggy rot the roots; use a gritty mix, ensure drainage holes are clear, and let the soil dry between waterings.
Prevent arp rosemary problems before they start
Most arp rosemary issues are care-mismatch, not bad luck. Dial in the basics:
- Common rosemary problems — the species this cultivar belongs to
- Common arp rosemary problems — our other guide for the same plant
- What's wrong with my plant? — the diagnosis apps compared
- Arp Rosemary watering schedule
- Arp Rosemary light requirements
- Best soil mix for arp rosemary
- Arp Rosemary temperature & humidity
- Full arp rosemary care guide
Looking for arp rosemary in general rather than its problems? Read the full arp rosemary care guide — light, water, soil and feeding.
Arp Rosemary problems — FAQ
Why is my arp rosemary winter wet, not just cold?
Even this hardy cultivar dies in cold, waterlogged soil; sharp drainage matters as much as low temperatures for getting it through winter.
Why is my arp rosemary powdery mildew?
Dense foliage in damp, still air develops white mildew; provide good airflow, avoid wetting the leaves, and don't overcrowd.
Why is my arp rosemary bare, woody base?
Old plants go leggy and woody low down; trim lightly after flowering and never cut back into leafless old wood, which seldom reshoots.
Why is my arp rosemary root rot in containers?
Pots that stay soggy rot the roots; use a gritty mix, ensure drainage holes are clear, and let the soil dry between waterings.