Growing 7 popular herbs

We look at the requirements of parsley, coriander, mint, oregano, thyme, rosemary and basil.

Parsley

Parsley is used in large quantities. So it needs plenty of feeding and regular watering to produce lush green leaves. If it gets too dry it'll go to seed.

You can raise parsley from seed. But germination takes a long time - sometimes more than a month - and can be patchy. If you're buying seedlings look for small plants in individual cells. This will mean the roots are disturbed as little as possible when you plant them out.

Tip: Remove the outside leaves to encourage growth from the centre.

Coriander

Coriander is a staple in Asian and Mexican dishes, and the leaves make a great pesto. But it's tricky to grow. When the weather is dry or very hot, it rapidly goes to seed - sometimes before enough leaves are produced to flavour even one meal. On the plus side, the seeds can be used to season dishes. And if you let the seed-headed plant die off in your garden you'll find new coriander seedlings popping up everywhere.

Don't buy seedlings. Coriander doesn't like being moved, so sow seeds where you want them to grow. Keep the seeds covered until shoots appear in 10 to 14 days.

Tip: For a lush crop, sow the seeds thickly in a container and help them along with fortnightly doses of high-nitrogen liquid fertiliser - or simply add a handful of sheep pellets to the potting mix. If you make sure the plants have enough water and harvest the leaves regularly, you'll have plenty of coriander for weeks.

Mint

Mint grows best in moist rich soil in partial shade. Its underground runners can spread throughout the garden - so keep it contained in a plastic pot (30cm diameter) sunk into the ground. Cut the bottom off the pot first.

Over time, the stems will head for the edges and leave the centre bare. So dig up the pot every two or three years and replant young rooted sections of stem.

Tip: Mint is susceptible to rust (brown spots on the leaves). Trim it to 3cm above the soil to promote new rust-free growth. If this doesn't work, get rid of the plant (not on your compost heap) and start again in another area of the garden.

Oregano

Oregano, like rosemary and thyme (below), needs full sun and a soil that's not too fertile to develop the essential oils that give the leaves their pungent flavour. It's a spreading plant - so allow it a space about 30cm in diameter and trim it regularly to keep it bushy and encourage new growth.

The plants will grow for several years. But they need rejuvenation every three to five years to keep them compact and productive. Dig up the plant in spring, divide it and replant a shoot that has good rootlets.

Tip: There are several varieties of oregano - true Greek oregano has the best flavour.

Thyme

There are many varieties of thyme, some very attractive but with little flavour.

The best varieties for cooking are common thyme, lemon thyme, caraway thyme and pizza thyme.

Tip: In winter trim the bush back by about two-thirds.

Rosemary

Rosemary is a good choice for pots or tubs - don't let it dry out, though. Picking out the tips will keep young plants bushy. Cut older bushes back to half that year's growth at the end of summer.

Tip: The trailing varieties are attractive but the upright types of rosemary are best for cooking.

Basil

You can raise basil from seed but it's easier and quicker to buy a punnet of seedlings. Basil needs warmth and regular watering. It can be tricky to grow in colder areas but will flourish in a pot in a sunny spot on your kitchen bench - you can raise six or more plants in a small pot. If you feed and water them regularly you'll have enough for an occasional batch of pesto.

Basil in pots should be watered from the bottom - sit the container in a deep dish to create a shallow water bath.

You may find the plants become infested with whitefly or aphids. Check them regularly - if the infestation isn't too advanced you may be able to wash off the pests. Some gardeners recommend spraying with a mixture of dishwashing liquid and water. If that doesn't work just throw out the plants, wash the pot and buy another punnet.

Tip: To encourage bushy growth, keep pinching out the growing tips.

More information

• 'The Cook's Herb Garden' by Mary Browne, Helen Leach, Nancy Tichborne.

More from consumer.org.nz

• Soil quality
• Growing vegetables

Report by Bev Frederikson