There is still time to plant garlic, says Gillian Vine.
Seeing a recent garden-centre advertisement for garlic was a reminder of an urgent late-autumn task.
The popular notion is to put in garlic cloves on the shortest day and harvest them on the longest.
However, in a cold winter, it would take a crowbar to break up the ground on June 21 and most summers, garlic tops are still green on January 21.
April is the optimum time to plant but getting garlic in by the end of May or early June still gives it a reasonable start so that, when the soil warms in spring, it sprints ahead.
Garlic (Allium sativum) belongs to a large family, which includes onions, leeks, shallots and numerous decorative plants with pink, white, mauve, blue or yellow flowers held in balls on strong stems.
Humans have eaten garlic, as well as onions and leeks, for at least 4000 years.
The health benefits have been known for centuries and it is believed eating alliums can reduce the risk of cardiovascular disease, heart attacks, strokes and some cancers, as well as keeping colds at bay.
These days, China is the world's top commercial garlic grower, producing 20 million tonnes last year, more than 10 times the amount grown by second-placed India.
New Zealand's total was a modest 900 tonnes in 2013, of which $700,000 worth was exported, mainly to Australia and Pacific countries.
In the late 1990s, cheap Chinese garlic flooded the market and New Zealand's garlic industry almost collapsed.
Thankfully, that is changing with growers of organic garlic, in particular, finding strong demand for their produce.
For the home gardener, garlic is an easy-care vegetable whose main requirement after planting is to be kept weed-free.
To grow garlic, start with a head or two from a garden centre, or use some you've grown.
Supermarket garlic may have been treated or have had the roots removed, so is not recommended.
Choose a sunny spot with rich soil and make sure every weed has been removed before planting.
Good drainage is important, too, or the bulbs may rot.
Break each head into individual cloves and press them into the soil, point up.
Space them about 15cm apart and allow 30cm between rows.
Some gardeners leave the tips above the soil but it does make the cloves a tempting target for birds.
If you miss out this season don't panic, as plants are available in garden centres in spring, although this is a more expensive way to grow garlic.
It takes about six months for garlic to reach maturity but it does depend on the season.
In a really good year, bulbs may be harvested in as little as four months, but six months is more common.
The main thing is to wait until the foliage starts to die before harvesting.
Dig garlic on a warm, sunny day and hang the plants to dry completely before storing in a warm, dry place.
A dry spot is vital, or garlic will absorb moisture from the atmosphere, causing it to rot.
Apart from A. sativum, three other alliums are referred to as garlic.
The most familiar is elephant garlic (A. ampeloprasum var. ampeloprasum), which reaches about 1m, compared with garlic's 50cm, and has very large cloves.
Although it is grown and used like garlic, this is actually a variation on the leek, as a comparison of the leaves shows.
Garlic chives (A. tuberosum) are Asian and are sometimes called Chinese chives.
Unlike true chives (A. schoenoprasum), they have flat leaves, with a central vein on the underside.
Not just for the vegetable garden, garlic chives can be used decoratively, as their edible white flowers are held on stems that sit well above the foliage.
They grow easily from seed sown from spring to autumn and mature clumps can be divided now.
Like common chives, they can be planted under roses to deter aphids.
Mentioned in some old gardening books as a milder form of garlic is rocambole (possibly (A. scorodoprasum or A. sativum var. ophioscorodon) but it seems to have vanished from cultivation in New Zealand.
Does any reader still grow it?
Eelworms, thrips and aphids are the main pests that cause damage to the onion clan, including garlic, while white rot and downy mildew are the principal diseases.
White rot attacks the root area and is the most serious for a bad infestation is likely to result in not being able to grow good onions, garlic or leeks for years to come.
As with all vegetables, crop rotation is an important tool in disease prevention and garlic should not be planted this year where leeks or onions were last season.
