Gardening: Ginger

You get the best results with most plants when you provide conditions as close to those of their place of origin as possible, so a hot, humid atmosphere and partial shade are required for a tropical plant such as ginger. Damp, fertile soil or compost is also essential. Against such odds, there are gingers that will grow in Scotland. A warm conservatory, with some, but not full, sun, is the ideal location, where they should be watered and fed regularly.

At Kew Botanic Garden, mature plants are grown in the tropical nursery, with a temperature between 18C and 25C and with 70-90 per cent humidity. They are watered every day for most of the year, but less regularly during the winter. The plants also get a fortnightly balanced feed. As you'd expect, this is the gold standard, but my potted galangal copes quite well with 18C, frequent watering and the liquid drained off from my wormery.

The ginger most of us use in the kitchen comes from the rhizomes of Zingiber officinale. This was one of the earliest spices the Greeks and Romans got from the east, via Arab traders. But we now use many different gingers, including cardamom (Elettaria cardamomum) and turmeric (Curcuma longa).

Gingers such as Z officinale grow very differently to most plants. Their shoots grow to around 1.2m every year from buds on rhizomes. When looking at the shoots, you might assume they were "normal" stems, but they're called pseudostems because they're formed by a series of leaf bases wrapped very tightly round each other. When looking at the shoots, I'm almost reminded of the way leek skins wrap round each other.

Ginger's long, narrow leaves grow outwards alternately. The flowering heads, capping shorter stems, are cone-shaped spikes comprising greenish, leaf-like bracts. The pale yellow flowers protrude just beyond the outer edge of the bracts.

Although the flowering heads rarely appear on cultivated Z officinale, many of the specimens grown as houseplants do flower reliably. These are usually hedychium species. "Hedys" is ancient Greek for sweet and "chios" means snow, and with its wonderfully fragrant white flowers, H coronarium fits the bill perfectly.

Hedychiums come in a wonderful range of colours including cream, lemon, apricot, lilac and maroon. H coccinium "Tara", which rightly won the RHS Award of Garden Merit, has appealingly fragrant orange flowers with prominent darker orange stamens.

Look out for other ginger cultivars such as H "Elizabeth", whose raspberry-coloured flowers are heavy with a superb scent. H coronarium "White Butterfly" sports clusters of delightfully scented white flowers you could mistake for butterflies. If you're looking for yellow flowers, meanwhile, H wardii offers up to five subtle lemon flowers to each bract. And H "Tahitian Flame" offers peach-coloured, scented flowers.

Most of us grow hedychiums and other zingiberaceae, such as Z officinale "Roscoe", for their unusual leaves, stunning flowers and overwhelming fragrance, but some also play a key role in the kitchen. My wife Jane is not unknown for her culinary skills and is always looking for more unusual spices to grow and use. So it's scarcely surprising we grow gingers such as cardamom. Like my galangal, the tropical cardamom thrives in a warm atmosphere (18-20C) and is regularly fed and watered. And good indoor light is sufficiently shady for it. Cardamom can reputedly reach 3m after three years, but mine is a paltry 45cm after two. Perhaps Jane has been making off with too many leaves.

Turmeric is another ginger we plan to start next year, growing it like our other gingers. With its distinctive yellow colouring, the spice is a default ingredient of Indian curries. If you want to try growing it, you might succeed with a rhizome from an Indian delicatessen, but a plant from Poyntzfield Herbs (poyntzfieldherbs.co.uk) will most likely succeed. This first-class nursery on the Black Isle carries a wide range of good and unusual herbs.