How to Grow Rosemary

Rosemary is a Mediterranean plant that wants sun, sharp drainage and neglect. Almost every dead rosemary was overwatered.

The conditions it wants

Planting

• Add grit. Mix 30% horticultural grit or coarse sand into the planting hole. This is the single most important step.
• Raise it. Plant slightly proud of the soil surface so water runs away from the crown.
• Do not enrich the soil. Rich soil makes soft, sappy growth that winter kills.
• Space plants 60–90 cm apart — airflow prevents mildew.

Watering

Water deeply, then let the top 5 cm dry out completely. In the ground, established rosemary usually needs no watering at all after the first year. In a pot, it needs more attention — terracotta dries faster than plastic.

Signs of overwatering: yellowing lower needles, soft black stems at the base, and sudden collapse. By the time you see it, root rot is usually advanced.

Pruning

• Never cut into bare old wood — it rarely regrows. Keep pruning to the green, leafy growth.
• Harvest from the top — snipping tips encourages bushy growth.
• Prune after flowering, not in autumn. Late pruning leaves soft growth that winter kills.
• Shape in spring once the worst frosts have passed.

Growing indoors

Rosemary struggles indoors for two reasons: too little light and too much water.

• Put it in the brightest window you have — south-facing ideally
• Water far less than you think; check the soil first
• Improve humidity by grouping plants, but never let the roots sit wet
• Expect slower growth indoors; a cool, bright porch is better than a warm living room

Winter care

Cold is survivable; wet cold is not. A rosemary in waterlogged soil at -5°C will die where a dry one survives -10°C.

• Move pots against a south-facing wall for radiated heat
• Raise pots onto feet so drainage holes are not blocked
• Do not water in freezing weather
• Do not wrap in plastic — it traps moisture

Propagating

Take 10 cm cuttings from non-flowering shoots in late spring. Strip the lower leaves, dip in rooting hormone if you have it, and put in gritty compost. Roots in 3–6 weeks. Rosemary from seed is slow and unreliable.

Common questions

Why is my rosemary turning brown and dying?

Almost always overwatering and root rot. Check drainage, stop watering, and take cuttings immediately in case the plant does not recover.

Can rosemary survive winter outdoors?

Down to about -10C in well-drained soil. In wet soil it can die at much milder temperatures. Wet cold is the real killer.

How often should you water rosemary?

Let the top 5cm of soil dry out completely first. Established plants in the ground often need no watering at all after the first year.

Why does rosemary die indoors?

Too little light and too much water. Give it the brightest window available and water far less than feels natural.