Horseradish is grown on only about 3000 acres in the U.S. Most
of it comes from California,
New Jersey, Virginia, Illinois and Wisconsin. An explanation of how the name
came into being was adapted from "Illinois Horseradish...A Natural Condiment", University of
Illinois Circular 1084:
The name "horseradish" is thought to have come from an English
adaptation of its German name.
Germans called the plant "meerrettich" (meaning "sea radish") because it grew
wild in European coastal areas. The German word meer (sea) sounds like "mare" in English.
Perhaps "mareradish" became "horseradish". The word "horseradish" first appeared in print in 1597
in John Gerarde's English herbal on medicinal plants.
A totally different plant (Wasabi japonica) is used to produce a
product called Japanese Horseradish or wasabi. It is propagated from crown sprouts,
rhizomes, or less commonly from tissue-cultured plants and from seed. It is prized by Orientals as a
flavoring for a number of foods. Although uniquely different in flavor from horseradish, it also has
many similar flavor characteristics.
Wasabi is an aquatic plant grown in cool, continuously running streams,
requiring much hand labor. There have been recent efforts to grow this plant in rice paddies and
in hydroponic greenhouses for the harvest of leaf petioles for the processing market. A new
variety called Wasabi Tainung No. 1, widely adapted and reportedly tolerant to a number of
important diseases, was developed at the Ali-san Chiayi Experiment Station and released in 1990 to
growers in Taiwan by the Taiwan Agricultural Research Institute.
Because of the difficulty in producing wasabi, and the demand for it, a
substitute has been developed using American horseradish to which synthetic flavor compounds and
the appropriate green food color have been added. Both wasabi and the substitute product are
marketed as a canned dry powder or frozen or fresh paste. In Japan, the fleshy plant stem
or leaf petioles of wasabi are also sold fresh in produce markets.
The following describes only production practices for horseradish common in the U.S.
Horseradish is divided into two general types, "common" and "Bohemian".
Maliner Kren is a "Bohemian" type from which many local selections have been made. Improved
Bohemian and Bohemian form the basis of the current industry. "Common" types have broad
crinkled leaves and are considered to have superior quality, while "Bohemian" types have narrow
smooth leaves, somewhat lower quality, but better disease resistance. Obtaining adequate
quantities of quality planting stock of the right variety is a major concern in horseradish production!
Use planting stock from root cuttings that have been trimmed from the
crop's main roots at harvest. Use root pieces with a diameter of 3/8 to 3/4 inches in diameter.
Cut root pieces 8-12 inches long leaving a square cut at the top, and tapered cut at the bottom, so
those planting will orient the root properly in the ground. Space rows 30-36 inches apart with
in-row spacing of 15-24 inches. About 8700-9700 root cuttings will be required per acre.
Horseradish plants may be produced through tissue culture. Although
more expensive, rapid increase of the desired planting material via tissue culture may be possible
by contracting with plant propagators having tissue culture capabilities.
Use deep loam or sandy loam soil types that have good drainage. It is
desirable to have a fair amount of organic matter in the soil as well. Shallow soils over hard subsoils
are not suited for good production.
The following are general recommendations. It is advisable to have a
soil test done on each field to be planted. Fields should be limed to a pH of 6.0-6.5. Manure may be plowed under at 12-20 tons/acre in the fall.
Nitrogen: 100-200 (N) lb/acre depending on soil type.
Phosphorus: 100-150 (P2O5) lb/acre
Potassium: 100-150 (K2O) lb/acre
Boron: 2-3 (B) lb/acre
Sulfur: 30-50 (S) lb/acre
The root cuttings should be about l/2 to 3/4 inches in diameter and from
8-14 inches long. These should have been cut with a slanting cut on the lower end and a square cut at
the top in order to determine the proper root placement in the soil. Plant roots as early in the
spring as ground can be prepared, usually in early April. About a year is required to produce a
crop. Since fields may be harvested in fall or spring, the spring harvest usually provides planting
stock for planting. Under conditions where planting stock is available, and roots have time to get
established, fall planting may also be feasible.
Roots may be placed in the soil either by transplanter or by hand.
Transplanters might need some modification to work most efficiently. The transplanting operation should
leave the root at an angle of about 45 degrees in the soil. This is very important for vigorous
establishment and growth.
For hand planting, furrows should be made that are 3-5 inches deep.
Roots are then dropped into the furrow making sure that all the tops are pointing in one direction, and
the roots at a 45 degree angle. Then push some soil over the lower end of the root and firm it with
the foot to hold it in place. A cultivator can be used to finish filling in the trench and covering
Some growers set the root so that several inches remain above the level
soil surface. Then the roots are covered by forming ridges in the rows with disk hillers. This
ridging also benefits the harvesting operation.
Whether roots are laid in trenches or placed at an angle in the soil, it
would be desirable to plant two or four rows together in the same direction. This allows cultivation of
the rows in the direction that the roots are set rather than against them.
Although irrigation early in the growing season is not required, greater
yields will be obtained if horseradish is irrigated during dry periods in August and September. The
benefits of irrigation will be greater on lighter soils where crops are more subject to moisture
Soil type does not affect the amount of total water needed, but does
dictate frequency of water application. Lighter soils need more frequent water applications, but less
water applied per application.
HARVESTING, HANDLING, AND STORAGE
Approximate yields range from 7,000 to 8,000 lb/A. Horseradish makes
its greatest growth in late summer and early fall. Harvest is usually delayed till October or early
November for best yield. Fields may be harvested in fall or spring.
Harvesting is usually not started until a frost has killed off the tops.
If harvesting is done before that, tops should be removed with a rotary cutter as close to the soil surface
as possible. Allow several days between leaf removal and harvest. If bad weather prevents fall
harvest, the roots can be harvested the following spring.
Harvest is usually done by using a modified 1 or 2 row potato harvester.
It is important to set the harvester deep to allow maximum recovery of roots and also to reduce the
number of volunteer plants that grow as weeds in subsequent years.
Before the roots are sent to the processor, small roots must be removed
as the planting stock for the next season. The small roots selected to be stripped from the large roots
should be about 0.5 in. in diameter and 10-14 inches long, and free from injury. The bottom of
each root should be given a slanting cut and the top a straight cut to indicate root position at
planting. Store the roots and planting stock at low temperatures and high humidity with good air
STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)
Horseradish should keep satisfactorily for up to 10-12 months at 30 to
32 F, relative humidity of 90-95%. A high relative humidity is essential for minimum deterioration
during storage. Perforated plastic bags or bin liners can aid in maintaining the high
humidity. Roots should be kept in the dark because they can become green when exposed to light. Roots
dug when the plant is actively growing do not keep as well as those conditioned by cold weather
before they are dug. Frequent inspection is storage is advisable. Horseradish can also be stored
over winter in cool cellars or in outdoor pits or trenches.
The requirements for marketing the roots are: A well-flavored root,
reasonably straight, without side shoots, and no mechanical or decay damage. The roots should be at least
8 in. long with a diameter of not less than 0.75 in.
Horseradish is commonly packaged in 60-lb sacks, 50-lb sacks, 5-lb
cello packages, or delivered in bulk for processing.
PEST CONTROL FOR HORSERADISH
THE PESTICIDES LISTED BELOW, TAKEN FROM THE PACIFIC NORTHWEST PEST
CONTROL HANDBOOKS, ARE FOR INFORMATION ONLY, AND ARE REVISED ONLY
ANNUALLY. BECAUSE OF CONSTANTLY CHANGING LABELS, LAWS, AND
REGULATIONS, OREGON STATE UNIVERSITY CAN ASSUME NO LIABILITY FOR
THE CONSEQUENCES OF USE OF CHEMICALS SUGGESTED HERE. IN ALL CASES,
READ AND FOLLOW THE DIRECTIONS AND PRECAUTIONARY STATEMENTS ON
THE SPECIFIC PESTICIDE PRODUCT LABEL.
USE PESTICIDES SAFELY!
Wear protective clothing and safety devices as recommended on the label.
Bathe or shower after
Read the pesticide label--even if you've used the pesticide before. Follow
closely the instructions
on the label (and any other directions you have).
Be cautious when you apply pesticides. Know your legal responsibility as a
pesticide applicator. You may be liable for injury or damage resulting from pesticide use.
Note that the state of Oregon requires reporting of agricultural pesticide use to the Oregon Dept. of Agriculture
under its PURS system.
WEED CONTROL FOR HORSERADISH
The Pacific Northwest Weed Control Handbook has no control entries for
this crop. Herbicides registered, but not
evaluated in the Pacific Northwest, include Dacthal and Roundup. Consult
labels for rates, restrictions, and weeds controlled.
Cultivate as often as necessary when weeds are small. Proper cultivation, field
selection and rotations can reduce or eliminate the need for chemical weed control.
Return to: | Beginning of This File | Index to Vegetable Production Guides |