Horseradish can be a bit of a giant in the garden with leaves reminiscent of Dock (Rumex). Used really fresh as either a herb or a vegetable it adds a real kick to your harvest!
Horseradish is easy to grow and the challenge may be preventing it from spreading too much . It makes a perfect container plant and as long as you are aware that is is invasive, it is easy to handle. The strong taste means that you need only small quantities so growing a single plant is ideal.
It can be grown from seed but is easier to grow from pieces of root called thongs. These can be bought all year round but planting is generally in Spring or Autumn.
Soil and Aspect
Horseradish thrives in any light rich soil, although it is not fussy and will prosper almost anyway where the soil has been prepared.
Ideally you should grow it in it's own area rather than among other crops. As with mint, it is possible to restrict the spread by planting in a planter. Choose a deep planter to accommodate the roots. The Haxnicks Potato Planter is ideal.
For a container use ½ manure and ½ compost as horseradishes love manure. Make some deep vertical holes with a dibber, then drop in a thong so that the top is 2in (5cm) beneath the surface of the compost and cover. Three thongs in a container is the maximum. You only need a tiny amount though, so as I mentioned before you may only want one plant. Place in a sunny or partially shaded spot or in the greenhouse if you are starting them off early. Growth will soon appear above the surface of the soil in Spring.
Once you have established your plants you can divide them to get more. Plant clumps or root sections out in the Autumn or Spring to increase your number of plants. If you are planting more than one then allow 30cm between them.
Harvesting and storage
If you intend to lift plants completely that have been growing on lighter soils then you must make sure to remove all of the root to avoid regrowth and deep roots travelling across your plot.
Horseradish is best harvested as it's needed during the growing season. If using the leaves then these are certainly best used fresh from the plant and harvested when young.
For winter use, the roots can be lifted and stored in trays of moist sand for up to two months
Fresh Horseradish has a stronger flavour than shop bought versions so do be prepared and taste as you go along!
The roots are the main harvest from the Horseradish. They can be simply peeled and grated for use in salads or mixed with creme fraiche and vinegar to make a sauce for use with roast and cold meats.
The leaves can be used in mixed salads in the same way that you might add herbs and also in dishes where you may like to add them to Chard or other leafy vegetables to add depth of flavour.