Horseradish (Armoracia rusticana) is a large leaved, hardy European
perennial herb that has been a culinary favorite for more than 3,000 years.
Horseradish was used in England long before the Romans introduced the
English to other herbs and spices. This fiery herb thrives in temperate
climates and in the cool, high altitudes of tropical countries. Horseradish
grows best in deep, rich, moist loamy soil, in a sunny location. Roots tend
to be malformed and yields are reduced on hard, shallow, stony soils.
Preparation & Planting
Before planting Horseradish, spade or rototill the soil to a depth of
8-10 inches, turning under or mixing in generous amounts of well-decayed
compost or other organic material. Incorporate either a complete garden
fertilizer (10-10-10) at a rate of 1 lb./100 sq ft. Or a liberal amount of
well-decayed manure into the soil. Fresh or partly fresh manure used before
planting will cause excessive top growth and forked roots. Let the worked-up
soil settle a few days before planting.
Plant root cuttings, sometimes called “sets”, in early spring as soon as
soil can be worked. Space the sets 1 foot apart, setting them vertically or
at a 45 degree angle. If angled, make sure that the tops point along the
rows in the same direction. This makes cultivating easier. Cover the sets
with 2-3 inches of soil.
Weed control is especially important early in the season when the plants
are relatively small. It is best to cultivate in the same direction that the
sets were planted. Mulch around each plant with organic material such as
compost or leaves. It will benefit the plants by retaining moisture in the
soil, keeping the soil cooler, and controlling weeds.
To grow high quality Horseradish, lift and strip the roots twice, first
when the biggest leaves are 8-10 inches long and again 6 weeks later. To
lift and strip, carefully remove the soil from around the upper ends of the
main root, leaving roots at the lower end of the set undisturbed. Raise the
crown and remove all but the best sprout or crown of leaves. Rub off all
small roots from the crown and sides of the main root, leaving only those at
the bottom. Return the set to its original position and replace the soil.
Horseradish makes its greatest growth during late summer and early
autumn. For this reason, delay fall harvest until late October or early
November, or just before the ground freezes. Harvest by digging a trench
12-24 inches deep along one side of the row. Then, working from the opposite
side of the row with a shovel or spading fork, dig the roots. Use the tops
as a handle for pulling them laterally from the soil. Trim the green tops so
there is only one inch left. Trim off side and bottom roots saving those
that are 8 inches and longer for next spring’s planting stock. Cut the roots
squarely across at the top and sloping at the bottom. This will make it
easier to distinguish which end to set upright at planting time.
Tie cleaned root cuttings in small bundles and place them in moist sand.
Over-winter Horseradish in a root cellar or basement that stays between
32-19 degrees during the winter. The roots must not be exposed to light,
otherwise they become green. If storage and temperature conditions cannot be
met, an alternative would be to harvest
Horseradish in spring rather than fall. Dig the roots as soon as new growth
starts to appear in spring. Replant lateral roots for next spring’s crop.
Roots left in the ground for two growing seasons become stringy and woody.
Storage & Use
Store Horseradish roots for fresh grinding in dark plastic wrapping in
the refrigerator. Protect the roots from light to prevent their turning
The most common way of preparing horseradish for table use begins with
peeling or scraping the roots. Grate the root directly into white wine
vinegar or distilled vinegar. Avoid using cider vinegar, as it causes
discoloration in the grated Horseradish within a rather short time.
Depending on your preference, the vinegar may be slightly diluted. Bottle
the Horeradish and cap the containers as soon as possible after grating.
Refrigerate at all times to preserve the pungent flavor. Freshly grated
Horseradish will keep only for a few weeks. Then prepare a fresh supply.
Horseradish may also be dried, ground to a powder and put up in bottles
in a dry form. Dried Horseradish will keep much longer than the freshly
grated product, but is generally not as high quality.
Occasionally, Horseradish may suffer from root rot. Select only
disease-free root cuttings to use as planting stock. Rotate the planting
site so it is not grown in the same place more often than every 3-4 years.
Certain insects can also be a serious pest on Horseradish foliage. Use the
following pesticides for the following insects: (Consult product labels
for legal restrictions, rates and complete instructions!!!!!!)
What Makes Horseradish Hot?
Horseradish is a member of the mustard family (sharing lineage with its
gentler cousins, Kale, Cauliflower, Brussel Sprouts and the common Radish)
and is cultivated for its thick, fleshy white roots. The bite and aroma of
the Horseradish root are almost absent until it is grated or ground.
During this process, as the root cells are crushed, volatile oils known as
isothiocyanate are released. Vinegar stops this reaction and stabilizes
the flavor. For milder horseradish, vinegar is added immediately.
Horseradish is said to help fruit trees. It helps prevent brown rot on
apples and potato diseases.
Once established, Horseradish is very hard to get rid of and spreads
very rapidly, so grow it in a sunny, out-of-the-way corner.