How to grow Horseradish in Australia

Where to plant

Horseradish grows in all climates but is most pungent in areas with cold winters. It likes full sun or light shade and moist soil. It tolerates dry conditions and poor soil, but humus-rich, moist soil gives larger roots.

Contain it. Horseradish spreads by its roots and can become invasive, and every piece of root left behind can reshoot. Gardening Australia recommends growing it in a pot or large tub; a bed lined with a deep barrier also works. Choose a permanent spot well away from other garden beds.

• South East Queensland, the Northern Rivers, Sydney, Melbourne, Adelaide and Perth: plant root pieces from June to September. In warm areas roots are milder.
• Canberra and Hobart: plant root cuttings from August to October as the soil warms. It is fully hardy and very easy, so keep it contained.
• North Queensland and Darwin: our calendar marks these as unsuitable, as horseradish needs a cold winter rest and rots in wet season soil. Grow daikon or mustard greens for heat instead.

How to plant

1. Fill a large tub or contained bed with good potting mix or garden soil enriched with compost and a little fertiliser.
2. Plant root pieces or small crowns in late winter or early spring, about 15 cm apart in a tub, or about 40 cm apart in a bed.
3. Plant small root pieces or a divided clump, spreading the roots and keeping the crown central and at the depth it was growing. Even small pieces of root will grow.
4. Mulch and water in.
5. Water during dry spells while the leaves are growing.

Watering and feeding

Water during dry spells to keep the roots growing; moist soil gives bigger, more tender roots. Ease off in winter when the plant is dormant.

Rich potting mix or compost-enriched soil needs no feeding for a while. A small handful of blood and bone in spring is plenty.

Harvesting

Dig roots in winter while the plant is dormant, any time from late autumn to early spring, once the plant has grown for about a year. In a tub, cut back the old foliage and tip the whole tub out into a wheelbarrow, which is easier on your back and keeps every root piece contained. Keep the larger roots for the kitchen and replant the smaller heads or root pieces in fresh mix with compost.

Put any unwanted root pieces in a bucket of water until they rot, so they cannot regrow. Do not compost live horseradish root.

Growing in pots

A large, deep tub at least 40 cm deep is the best way to grow horseradish, as it stops the roots spreading. Gardening Australia's presenter grows hers in a recycled bin, harvesting and dividing every couple of years and replanting the six strongest divisions about 15 cm apart in refreshed mix.

Using it

Scrub small roots or peel older pieces, then grate or blend them, ideally outdoors or near an open window, as the fumes are highly pungent. Pack the grated root into a jar with a little salt and cover it with vinegar. For a creamy sauce, mix some with cream or crème fraîche.

Propagation and saving seed

Horseradish is grown from root cuttings or divisions. Each piece of root with a bud regrows readily, so propagating it is easy; the hard part is stopping it spreading.