How to grow Rosemary in New Zealand
Rosemary is a tough, fragrant Mediterranean shrub with needle-like leaves and blue, pink or white flowers that bees love. Once established it shrugs off drought and cold, and it grows in every part of New Zealand given sun and free-draining soil. One plant keeps a kitchen in sprigs for years.
📖 Our full guide: How to Grow Rosemary in NZ: Planting, Pruning and Harvest
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| Northland | August to May | |
| Auckland | August to May | |
| Waikato & Bay of Plenty | August to May | |
| Central North Island | August to May | |
| Wellington & Lower North Island | August to May | |
| Nelson & Marlborough | August to May | |
| Canterbury | August to May | |
| Otago & Southland | September to April | Plant Sep to Apr so roots establish before the hard frosts. |
| Central Otago | September to March | Plant Sep to Mar so roots establish before the hard frosts. |
Where to plant
Plant rosemary in a hot, sunny spot with good air circulation and room to grow. It needs free-draining soil; on heavy clay, plant on a slight mound with gypsum in the bottom of the hole, as wet roots are the main thing that kills it. It suits containers, walls and banks, and makes a fragrant low hedge.
- Northland to Canterbury: plant at almost any time of year, though spring to autumn is best.
- Otago, Southland and Central Otago: plant from September to April (to March in Central Otago) so the roots establish before the hard frosts.
Choosing a variety
- Upright types make a bushy shrub or hedge.
- Prostrate or trailing types spill over walls and the edges of pots.
- Flower colours range from blue and purple to pink and white.
How to plant
- Buy a plant or strike a cutting; seed is slow and the seedlings vary.
- Dig a hole twice as wide as the root ball and the same depth, and mix compost into the backfill.
- Set the plant at the same depth it grew in the pot, firm gently and water in.
- For a low hedge, plant about three plants per metre and trim regularly.
- Mulch with bark or straw, keeping it clear of the stem.
Watering and feeding
Water regularly in the first year while the roots establish, deeply and slowly so it soaks in. After that, rosemary is drought tolerant and needs water only in long dry spells. Never let a pot sit in a saucer of water.
Rosemary needs little feeding. A light dressing of compost or a slow-release fertiliser in spring is plenty; rich feeding gives soft, less fragrant growth.
Pruning and care through the year
- Trim lightly after flowering and through spring and summer to keep the plant bushy. Avoid cutting back into old, bare wood, which rarely reshoots.
- Replace old plants that have become woody and sparse.
- Watch for aphids and caterpillars on soft new growth.
Harvesting
Snip sprigs as needed all year, taking soft tips rather than woody stems. Rosemary dries well: hang small bunches somewhere airy and out of the sun, then strip the leaves into a jar.
Growing in pots
Rosemary does well in a pot at least 40 cm wide, filled with a free-draining potting or container mix, in full sun. Water when the top of the mix is dry and do not leave the pot standing in water.
Propagation
Rosemary strikes easily from cuttings. Take 10 to 15 cm tips of new growth in late spring or summer, strip the lower leaves, and push them into pots of free-draining mix. Keep them lightly moist out of direct sun until they root.
Companion planting
Rosemary likes it hot, dry and lean, so its best neighbours are other Mediterranean plants. Bees on its flowers help the whole garden.
Good companions
Pests and diseases
Rosemary has few problems in a sunny, free-draining spot. Wet soil is the main cause of death.
Pests to watch for
- Aphids Small insects clustered on soft new tips.
- Caterpillars Chewed leaves on new growth.
Diseases to watch for
- Root rot Sudden browning and death of the whole plant in wet, heavy soil.
- Powdery mildew A white coating on leaves in humid, still spots.
Common questions
Why is my rosemary dying?
The most common cause is wet roots, from heavy soil, a shady damp spot, or a pot standing in water. Rosemary needs sun and free drainage. Plant on a mound or in a pot of free-draining mix.
Can I grow rosemary from seed?
You can, but it is slow and the seedlings vary. Buying a plant or striking cuttings is much quicker and gives you the variety you want.
How do I prune rosemary?
Trim lightly after flowering and through the growing season to keep it bushy. Do not cut into old, bare wood, as it seldom regrows from there.
Does rosemary grow in the South Island?
Yes. Rosemary is cold tolerant. In Otago, Southland and Central Otago, plant between spring and early autumn so it is well rooted before the hard frosts, and give it the sunniest, best-drained spot.
How often should I water rosemary?
Regularly in its first year, then only in long dry spells. Established rosemary is drought tolerant, and overwatering does more harm than underwatering.
Sources we checked: Yates NZ: How to grow rosemary; Kings Plant Barn: Rosemary grow well guide.