Horseradish root is not only delicious, it's easy to grow in a garden. Choosing the right spot to grow horseradish will likely be the biggest consideration. To thrive, horseradish needs full sun and well-drained, slightly acidic soil. And for your sanity, it should be planted on its own. Horseradish is an aggressive spreader and will quickly take over your garden vegetables. To get the most out of your growing season, plant horseradish root cuttings in spring as soon as the soil thaws.
Prepare the soil. Till the soil to a depth of 1 foot using a roto- or hand tiller. Spread 4 inches of compost over the planting area, followed by 2 ounces of 16-16-8 fertilizer per square yard. Till the soil again, to a depth of 1 foot.
Dig a hole for each root cutting that is twice its length and width. Neighboring horseradish roots should be 2 to 3 feet apart.
Plant each root cutting. Horseradish root cuttings are cut so that one end is slightly tapered. This end should face downward. Grasp the root cutting by its larger end and hold it in the hole so that the top of the root cutting is flush with the surrounding soil. Back fill the hole as you continue to hold the end of the root cutting. Pat the soil down once the hole is filled and cover the top of the root with a 2-inch mound of soil.
Water the horseradish roots so the soil is moist to a depth of 2 feet. The soil should be kept moist at this depth until the cuttings establish themselves and produce new growth. After that, horseradish should be watered weekly with 1 to 2 inches of water. Horseradish is fairly drought tolerant, but regular watering will make the root more tender and its flavor more pungent.