Horseradish in the garden

I recently posted some images of freshly made horseradish mustard on a forum page and was fascinated to receive quite a few questions about growing horseradish. So for anyone who may be interested, I have put together the following information.

Botanical name

Horseradish in my garden

Armoracia rusticana

Family

Brassicaceae

Description

Horseradish is a hardy perennial and the perfect cold-climate crop capable of surviving winter temperatures to -20°F (-28°C). With leaves reaching between 60 and 90 cm high, its long tapering roots, which can be rich in vitamin C, calcium, sodium and magnesium, grow to be approximately 5 cm thick and up to 60cm long. The delicious, pungent flavour of the root is released by grating or cutting the root, but is neutralized by heat. Whereas the young tender leaves of the plant can be added to your salad leaves for a little zing.

With all this being said, one must be aware of the invasive nature of the horseradish plant and take this into consideration when planting it.

Growing

Cuttings taken from the roots of healthy horseradish should be planted out into enriched soil, in the spring (in Australia), taking care to plant it where its invasive nature is not going to create problems in the future. Green leaves will sprout in the spring and die back in late Autumn/Winter. Established plants may send up sprays of white summer flowers which are best removed so that the plant can put all its energy into the roots, and prevent unwanted seedlings. Keep free of weeds.

Difficulty:	Easy
Soil:	Deep well drained, enriched soil.
Position:	Sunny to lightly shaded.
Spacing:	30cm apart.
Propagation:	Root cuttings, division.
Sow and plant:	Spring (in Australia)
Watering:	Keep soil moist (it doesn’t like dry soil).
Climate:	Cold to cool temperate.
Frost tolerant:	Yes
Feeding:	Feed established plants through spring and summer with an organic liquid plant food. Add a mulch of aged manure around the emerging plants in spring.

	Enrich the soil regularly with compost and manure.
	Do not over-fertilise with nitrogen as this causes roots to split.
Companions:	Potatoes, fruit trees, brambles, grapes, sweet potatoes, strawberries, asparagus and rhubarb.

Problems

Cabbage white butterfly caterpillars and small snails are the main pests to watch for. Regularly check plants for caterpillars and remove and squash any that are found.

Harvesting

Plants need one or two seasons in the ground before they are ready to be harvested. While roots from an established clump can be harvested whenever you need it, it is at its best, and has the strongest flavour, if harvested from late autumn to early spring.

To harvest, use a garden fork and loosen the soil in a wide circle around the plant. Then use your hands to locate the direction that the taproot has grown. The main horseradish root will not be found going down, but running virtually horizontal in any direction it chooses! Follow this root, gently working the soil, to ensure you get the biggest and best roots. The roots easily break off if you just try to pull them out.

Freshly dug horseradish from my garden.

Storage

Roots the same diameter as your fingers are the easiest to work with. I use a scourer to wash and scrub them with and then leave them to dry on some paper towel. You can store unpeeled horseradish in an airtight container in the fridge for several weeks, or alternatively freeze them. If you freeze the horseradish you can grate what you need while it is still frozen and return the unused portion back to the freezer for another day.

For a little more convenience you can prepare some horseradish and keep it in the refrigerator. Simply add 2 tablespoons of white wine vinegar to a clean jar and stir in 1 teaspoon of sugar and ¼ teaspoon of sea salt. Then using a microplane, finely grate your horseradish, adding it as you go, ensuring that is totally coated with the vinegar solution. With this on hand you can quickly add it to any dish you choose, in no time at all!

Note: When peeling and grating horseradish, make sure you wear rubber gloves and work in a well ventilated area, preferably outside, it is worse than working with onion and chillies!

Uses in the Garden

As a spray, horseradish can prevent apple scab, and if sprayed at leaf fall and bud swell may lessen the incidence of bacterial infection in fruit trees.

To make the spray, pour 1 litre of boiling water over the top of 3 firmly packed cupfuls of roughly chopped horseradish leaves. Cover and leave to stand for 30 minutes. Strain, cool and use within a few hours. This spray is a good general fungicide.

By growing horseradish under fruit trees it helps to protect them from fungal issues.

Uses in the Kitchen

The more finely the roots are grated, the stronger the flavour – I like

Horseradish Mustard - Ready for the store of preserves (and gift

Horseradish Mustard prepared for a gift.

to use a microplane to grate horseradish with. A couple of things to note though, when peeling and grating horseradish make sure you wear rubber gloves and work in a well ventilated area, preferably outside – it is worse than working with onion and chillies; also horseradish is not cooked because it looses its pungent flavour during the heating process.

Horseradish grated into cream is the traditional way to use the root, but it can be added to other foods, including coleslaw and beetroot, or added to mustards and mayonnaise to liven the flavour. You can even steep vinegar with horseradish and then use the vinegar for pickling beetroot or livening up a salad.