A chief ingredient of a fiery sauce that is traditional used as an accompaniment to roast beef or grated into coleslaw, horseradish is a vigorous, hardy perennial that forms a mass of leafy growth, but is primarily raised for its pungent roots. Plants can become invasive and difficult to eradicate when grown in the ground - best kept under control by growing in pots or raised beds filled with rich, well-drained soil.
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- Trim leaves
Month by month
Looking after horseradish is a doddle. Keep plants well watered during the growing season, especially during periods of drought to prevent the foliage from slumping.
Give plants in pots a boost in summer by applying a balanced liquid fertiliser.
Very little work with secateurs is necessary. Simply snip off any damaged leaves to prevent the crop from become too unsightly, and remove dead growth from around the crown of the plants in autumn.
Unlike so many other edibles, this is a tough, easy to look after herb that is rarely troubled by any pests or diseases.
Plants can be grown by seed, but it is far easier to raise from pieces of root, known as thongs, which are available from specialist growers in spring or from pot-grown plants that can be bought all year round.
To grow in pots, fill with multi-purpose compost including peat free media, make some deep vertical holes with dibber, then drop in a thong so that the top is 5cm (2in) beneath the surface of the compost and cover. Three thongs in a 30cm (12in) container is ideal. Place in a sunny or partially shaded spot. Growth will soon appear from above the surface of the compost or soil in spring.
It is also easy to grow in garden soil but can become a weed unless carefully managed.
Horseradish is harvested once the leaves die back in autumn, ideally after frost, which enhances its flavour.
Tip the plant out of its container and remove about half of the slender white roots. Replant the remaining roots back in the container, in fresh potting compost. The replanted roots will burst back into growth in spring, sprouting a flush of new leaves.
If the horseradish is growing in a raised bed, simply lift what you need with a garden fork.
Harvesting some of the roots annually helps to control the spread of this very vigorous plant.
Horseradish roots are best used fresh, but if you have too many, you can wash, grate and dry them.
Alternatively, store the roots until you want to use them – bundle them together in a wooden box or tray and cover with damp sand, then place somewhere cool, dark and frost free.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.