HORSERADISH PLANTING GUIDE

for the

HOME GARDENER

Horseradish is grown primarily as an annual, and to a limited extent, as a perennial crop. When grown as an annual, it needs warm temperatures during the summer growing season and cooler temperatures in the late summer and fall to enhance root development. In the annual system, the crop is usually planted in the early spring, and the entire root mass is harvested after the first killing frost in the fall. In the perennial system, upright, thickened, underground shoots arising from a deeply planted “mother” root are harvested every other year, with the original plant left in the field for regeneration. Perennial fields may stay in production for 10 to 20 years. 

SITE SELECTION - Horseradish grows best on rich, moist, deep friable loam or sandy loam soils rich in organic matter. The bed should be weed free and it needs good drainage to produce quality roots. Horseradish grown on soils with shallow, hard subsoils frequently produces highly branched roots of poor quality and poor useable set numbers and sizing.  

SITE PREPARATION - Horseradish tolerates a wide soil pH range of 5.5 to 6.8.  A balanced application of N(nitrogen) P(phosphorus) and K(potassium) should be broadcast and incorporated prior to planting.

PLANTING - Rows can be spaced three to four feet apart, with 10  to 12 inches between plants in the row. Sets are manually planted by laying them on the soil surface horizontally at a slight angle, with the head-end placed slightly higher as the set is placed in the ground.  The planted end of the set should be 1-2 inches below the soil surface. After laying out the sets, mound the soil to cover the sets to a depth of approximately five to eight inches and 18 to 24 inches across.  Keep in mind that just about any size root piece will result in a viable plant. 

FERTILIZER, IRRIGATION & WEED CONTROL - Horseradish does not need a lot of fertilization, however you can apply a 10-10-10 fertilizer to the bed in the Spring.  Weeding is essential and the beds should be kept weed free.  Depending on soil moisture-holding capacity, irrigation during dry periods, particularly in late summer to fall, can improve your yields. Studies have shown that most primary-root sizing occurs during the mid to late fall period, and not during the summer.

HARVESTING - Harvest roots the second Fall after planting. When the leaves have been killed by frost, loosen the soil around the horseradish and lift the root. Shake off any remaining dirt. Wash and dry the root. Sections of root that are @ 3/4 inch in diameter and 10 inches long can be replanted for your next year's crop. Just cut the top of the root off square and trim the bottom of the root at an angle so you remember which end is the bottom. If they are not harvested, the roots will need to be divided every other year.