People have been growing and eating horseradish for more than three millennia, according to the University of Arkansas. Follow the footsteps of ancient gardeners, and plant this spicy herb in your backyard garden. For optimal harvest, plant horseradish directly in the ground as soon as the soil is warm enough to work with a shovel.
Prepare the gardening site. Use a gardening implement to break up the soil to a depth of 10 inches.
Mix 3 to 4 inches of compost into the soil. Horseradish plants thrive on well-drained, moist soil, conditions that a liberal amount of compost can create.
Fertilize the planting site. The University of Minnesota suggests using any standard all-purpose garden fertilizer, like a 10-10-10 granular product, spread at a rate of 1/2 lb. for every 50 square feet of gardening space.
Plant the horseradish sets, a term for the horseradish plant's root cuttings. Bury each set 2 inches below the soil surface, and separate the sets by approximately 12 inches. For best results, angle the cuttings so that one end is pointing toward the soil surface at a 45-degree angle, according to the University of Minnesota.
Water the area once a day, moistening the soil to a depth of 4 to 5 inches. The plants will sprout within a couple weeks, and most horseradish varieties will be ready for harvest within six months, suggests the University of Arkansas.