Troubleshooting
Tuscan Blue Rosemary problems — and how to fix them
Tuscan Blue Rosemary (Salvia rosmarinus 'Tuscan Blue') 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.
Root and stem rot (Phytophthora)
The most common killer; caused by overwatering or poorly drained soil. Ensure sharp drainage and water only when soil is fully dry.
Botrytis (grey mould)
Favoured by wet, humid, poorly ventilated conditions. Improve airflow; avoid overhead watering; remove dead inner stems to open up the plant.
Legginess after neglect
If left unpruned, rosemary becomes woody and leggy. Prune lightly after flowering in spring, never cutting back into old, bare wood.
Frost damage in severe winters
Tuscan Blue is slightly less hardy than some cultivars. In USDA zone 7 or during prolonged hard frosts in the UK, wrap with fleece or move container-grown plants under glass.
Rosemary beetle (Chrysolina americana)
Metallic green-purple beetles and their larvae strip leaves. Hand-pick adults and larvae; shake plants over a cloth to dislodge them.
Prevent tuscan blue rosemary problems before they start
Most tuscan blue rosemary issues are care-mismatch, not bad luck. Dial in the basics:
Tuscan Blue Rosemary problems — FAQ
Why is my tuscan blue rosemary root and stem rot (phytophthora)?
The most common killer; caused by overwatering or poorly drained soil. Ensure sharp drainage and water only when soil is fully dry.
Why is my tuscan blue rosemary botrytis (grey mould)?
Favoured by wet, humid, poorly ventilated conditions. Improve airflow; avoid overhead watering; remove dead inner stems to open up the plant.
Why is my tuscan blue rosemary legginess after neglect?
If left unpruned, rosemary becomes woody and leggy. Prune lightly after flowering in spring, never cutting back into old, bare wood.
Why is my tuscan blue rosemary frost damage in severe winters?
Tuscan Blue is slightly less hardy than some cultivars. In USDA zone 7 or during prolonged hard frosts in the UK, wrap with fleece or move container-grown plants under glass.
Why is my tuscan blue rosemary rosemary beetle (chrysolina americana)?
Metallic green-purple beetles and their larvae strip leaves. Hand-pick adults and larvae; shake plants over a cloth to dislodge them.