Gardening: Three leaves are lucky too

Although the four-leafed clover is considered lucky, any clover cultivar will be good for your garden. Photo / Meg Liptrot

Meg Liptrot has a swag of reasons toencourage us to sowclover in our lawns

It's not just a four-leafed clover that will bring you luck - the standard three leaves will do. My lovely Irish hairdresser thought clover was found only in Ireland, bless her, and was surprised to hear it had flowers.

In fact, the pressed four-leaf clovers found in lucky souvenirs aren't likely to be clover at all. One "authentic" four-leaf clover I spotted online is actually a leaf of marsilea quadrifolia - an aquatic fern. Another imposter is Oxalis tetraphylla, which is known as "four-leafed sorrel" or the "Iron Cross".

The white clover most commonly seen on New Zealand farms (Trifolium repens) is the species of clover recognised most frequently as the true shamrock in Ireland.

These bee-friendly pioneer plants are fundamental ingredients to New Zealand's successful agricultural heritage. Clover is valuable pasture for grazing animals, and the flowers offer nectar for bees. It even produces its own fertiliser.

Clover plants have the ability to fix nitrogen out of the air and use it, via a symbiotic relationship with a species of nitrogen-fixing bacteria.

These bacteria form nodules on the plant's roots. The bond between plant and rhizobium bacteria benefits both partners - the roots absorb the nitrogen essential for leaf growth via the root nodules formed by the bacteria. The bacteria, in turn, feed on carbohydrates produced in the roots.

We can harness the power of clover to improve the soil in our gardens and orchards. Bees thrive on clover nectar, so fruit trees get two benefits - nitrogen for free and bees for pollination and more fruit.

As old clover plants break down into the soil, nitrogen and organic matter improve soil fertility and aeration.

Clover is hardy and should be included more often in lawn seed and grass verges as a companion to turf grasses, not just on farms. Grasses are more durable to heavy foot traffic, but clover keeps the soil fertile, avoiding any need for fertilisers.

Clover has deeper roots and is more drought-tolerant once established. They are recommended for developers to protect soil.

A clover lawn will help bring bees into your garden. Bees need all the help they can get these days as their populations are in decline around the world. If your kids run around barefoot on your lawn, sow clover seed around the edges instead, or mow the flowers where necessary. Bees are mainly active during the heat of the day.

There are an incredible number of cultivars.

Crimson Clover (Trifolium incarnatum) is a gorgeous, tall-growing clover species which would look good in any flowering border. Sow crimson clover seed in late summer to early autumn. The plant is dormant in winter, then grows to an impressive height of 1m in spring, with dramatic dark red elongated flowers in early summer. You can chop the plant up and dig in as a green manure crop, or leave to flower to encourage bees and beneficial insects.

Red clover, really a pinky-mauve colour, is a different species to crimson clover. It is used less frequently in pasture than white clover, but is still one of the world's main forage legumes and is used for soil improvement and hay production.

It has oestrogenic qualities, so it can affect the fertility of stock, but is valuable for cereal production. It contains phytoestrogens and is used in herbal medicines, for menopause hot flushes.

Subterranean clover is a species which doesn't have the classic clover flower, so it's not as attractive to bees. But it has been found to be a valuable grazing species in times of drought. Birdsfoot trefoil (Lotus corniculatus) is a leguminous alternative to clover. It is a small yellow-flowering plant which tolerates low pH and poorly drained soils.

If the soil wasn't quite so dry right now, because of drought conditions around the country, it would be a prime time to be sowing clover. But clover needs reasonable moisture to germinate, so wait for sustained rainfall and for soil moisture levels to recuperate before sowing.

So, there are plenty of reasons to consider yourself lucky if you have clover in your garden.

Rolling in clover

• You'll need luck to find a four-leafed clover. It's estimated that, for every one found, there are 10,000 three-leafed clovers.

• The scientific genus of clover is Trifolium, meaning "leaves divided into three leaflets". It is said St Patrick used the three leaflets of a clover, or trefoil (shamrock) leaf to demonstrate the doctrine of the Holy Trinity.

• The three leaflets of the shamrock represented the sacred triad for the Irish druids in pre-Christian pagan times, and was considered to ward off evil. Officially, Ireland's national emblem is the Celtic harp.

Clover suppliers

• kaiwakaorganics.co.nz for orchard herbal ley seed, which includes white, red and subterranean clovers. Sow clover seeds in spring and autumn when soil is moist and warm.

• kingsseeds.co.nz for crimson clover, plus mixed "herbal ley" seed for grazing animals which includes red clover.

• specseed.co.nz for a large range of bulk white, red, annual and perennial clovers and alternatives such as birdsfoot trefoil for large areas such as subdivisions, lifestyle blocks and farms.