How to grow Basil in New Zealand
Basil is the classic summer herb, quick to grow and the perfect partner for tomatoes, garlic and lemon. It is a frost-tender annual that needs warm soil and warm nights, so in most of New Zealand it is sown or planted from late spring and picked until the first cold snaps of autumn. Pinching out the tips keeps it bushy and leafy for months.
📖 Our full guide: How to Grow Basil in New Zealand
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| Northland | October to February | |
| Auckland | October to February | |
| Waikato & Bay of Plenty | October to February | |
| Central North Island | December | Sulks in cold nights. Wait until December or grow it under cover. |
| Wellington & Lower North Island | November to February | |
| Nelson & Marlborough | November to February | |
| Canterbury | November and December | |
| Otago & Southland | December | |
| Central Otago | December |
Where to plant
Grow basil in a warm, sunny spot in well-drained soil enriched with compost or blood and bone. It also does well in part shade and in pots. It stops growing in cold nights and is killed by frost, so do not rush it out in spring.
- Northland, Auckland, Waikato and Bay of Plenty: sow or plant from October to February. In humid northern summers, water at the base and space plants for airflow to reduce downy mildew.
- Wellington and Nelson and Marlborough: sow from November to February.
- Canterbury: sow in November or December, once frosts are over.
- Central North Island: basil sulks in cold plateau nights. Wait until December, or grow it under cover.
- Otago and Southland and Central Otago: sow in December, or grow it in a sunny glasshouse or on a warm windowsill.
Choosing a variety
- Sweet Genovese: the classic large-leaved Italian basil for pesto and caprese salad.
- Thai basil: purple stems and an anise flavour, for Thai, Vietnamese, Lao and Cambodian cooking.
- Greek basil: tiny leaves on a compact mound, ideal for pots.
- Lemon basil: narrow leaves with a strong citrus scent, good with fish.
- Holy basil (tulsi): used in India for herbal tea and revered in Hinduism.
- Dark Opal and other purple basils: striking colour with a milder flavour, good in salads and vinegars.
How to plant
- Sow seed in trays of seed raising mix in a warm spot, or direct into warm soil once frosts are over.
- Sow about 0.5 cm deep and keep the mix moist; seedlings appear in about 10 days.
- Plant out seedlings once nights are warm, about 25 cm apart, into soil enriched with blood and bone or compost.
- Water in and mulch with pea or lucerne straw.
Watering and feeding
Keep the soil moist but never waterlogged. Water in the morning at the base of the plant rather than over the leaves, which helps prevent leaf diseases.
Feed every week or so with a liquid fish and seaweed plant food or a vegetable and herb fertiliser to keep fresh leaves coming.
Pruning and care through the year
- Pinch out the growing tips regularly to make plants bushy, and remove flower spikes as they form to keep leaves coming.
- Let one or two plants flower late in the season if you want to feed bees.
- Pick all the leaves before the first frost, as the plants die with the cold.
Harvesting
Start picking about six weeks after sowing. Pick the top pairs of leaves just above a leaf joint, which also keeps the plant bushy. For the best flavour, pick in the morning after the dew has dried but before the day heats up.
Stand cut stems in a glass of water on the bench rather than in the fridge, as basil blackens in the cold. To keep it for winter, dry the leaves, freeze them in butter cubes or make pesto.
Growing in pots
Basil grows well in a pot at least 15 cm wide, in quality potting mix, in full sun or part shade. Keep it moist and feed weekly, as pot plants run out of food quickly. Potted basil can go on a warm windowsill in cool districts.
Using it
Use basil fresh in pesto, caprese salad, pasta sauces and on pizza, adding it at the end of cooking. Thai and holy basil go into curries, stir-fries and teas.
Companion planting
Basil fits neatly between summer vegetables that like the same warmth.
Good companions
- Tomato The classic pairing in the garden and the kitchen; both like warm, sunny, well-watered beds.
- Capsicum Another warm-season crop with the same needs, and basil fills the gaps between plants.
- Oregano A herb that suits the same sunny spot.
Keep apart
Avoid planting these close to basil.
- Rue A strongly scented herb usually kept away from basil and other culinary herbs.
- Sage Sage prefers drier soil than basil, so they are better in separate spots.
Pests and diseases
Basil is easy, but slugs and snails love the seedlings and humid weather brings leaf disease.
Pests to watch for
- Slugs Seedlings chewed off overnight, with silvery trails.
- Snails Ragged holes in leaves and silvery trails on plants and soil.
- Aphids Small green insects covering stems and leaves.
- Whitefly Small white insects that fly up when disturbed, with yellow or mottled leaves.
- Caterpillars Chewed leaves and caterpillar droppings.
Diseases to watch for
- Downy mildew Yellowing leaves with grey to purplish fuzz underneath, worst in humid weather. Water at the base and space plants for airflow.
- Fusarium wilt Plants that wilt and yellow, often on one side, and do not recover. Remove them and grow basil in a different spot next year.
Common questions
When should I plant basil in New Zealand?
Once the soil and nights are warm: from October in Auckland and the north, November in Wellington, Nelson and Canterbury, and December in the central North Island, Otago and Southland. Basil is killed by frost and sulks in the cold.
Why is my basil going black?
Usually cold. Basil blackens in cold nights and in the fridge. Store cut basil in a glass of water on the bench and wait for warm nights before planting out.
How do I stop basil from flowering?
Pinch out the growing tips regularly and remove flower spikes as soon as they appear. Regular picking does the same job.
Can I grow basil indoors over winter?
Yes, on a warm, sunny windowsill, though growth slows in winter light. In most of New Zealand basil is treated as a summer annual and resown each spring.
How do I keep basil for winter?
Dry the leaves, freeze them in butter cubes or make pesto and freeze it. Pick everything before the first frost.
Is basil good for bees?
Yes. Its flowers are a strong draw for bees, so let a plant or two flower at the end of summer.
Sources we checked: Yates NZ: How to grow basil; Yates NZ: Common problems of basil; Kings Seeds: Basil Genovese Giant.