It's easy to grow and lovely to eat, writes Andrew Unsworth - just don't sniff it I found my copy of Mrs M Grieve's Modern Herbal, first published in 1931, to see what she said about horseradish. If she is to be believed, you can use it to remove freckles, treat dropsy and chilblains, control whooping cough, cure hoarseness or deworm children - depending on what you mix it with.Alternatively, you can just eat horseradish with fish or roast beef, and it's great as a braai condiment. Good horseradish is far hotter than mustard and can blow a hole through your sinuses, which can be quite pleasant. The bottled sauces on the market are a meek version, but it is easy to grow and make your own.Horseradish has been around since the ancient Egyptians, but its use as a food is more recent, with Germany and Denmark teaching the rest of us that it is tasty. It has long been popular in Central and Eastern Europe, where it is called khren, and is sometimes mixed with beetroot. It has nothing to do with horses - "horse" once meant coarse, setting it apart from other edible radishes.The broad-leafed plant (Armoracia rusticana) is decorative enough to be grown anywhere in the garden. Dig up the roots at the end of summer or whenever you need some. You can't pull them up as they snap off. Horseradish is part of the Brassicaceae family, related to mustard, wasabi, broccoli and cabbage. It's so similar to wasabi that it is used to make it when the real stuff is in short supply.story_article_right1Growing it is easy, perhaps too easy. Buy plants or a packet of fresh roots from the greengrocer and plant in well-dug and composted soil. You can dig it up at the end of summer or leave the plant for two years, but after that the roots get woody. It grows better in areas with cold winters. Any bit of root you leave in the ground will probably grow again, which is why it's almost too easy to grow - it can become a weed.HOW TO MAKE ITWork in a well-ventilated area as the root can be very strong. Peel and grate the roots by hand or in a food processor with a little water. If you do it in the processor, don't sniff it!Use it in a sauce or bottle it in vinegar, ensuring the vinegar covers the grated root. Add a pinch of salt as soon as you can, and seal. If left exposed it quickly loses its pungency. It also loses its taste if cooked. You can mix grated or blended root with lemon juice or sour cream. Americans blend it with mayonnaise. Tewkesbury mustard, mixed with horseradish, has been around for so long Shakespeare referred to it...