Extension Educator, Horticulture
Illinois is not just a leader in corn and soybean production. Illinois also leads the country in the production of processed pumpkins, freeze dried herbs and horseradish. More horseradish is grown in Illinois than any other place in North America. Most of it is grown in southwestern Illinois near St. Louis in a region historically known as the American Bottoms near the Mississippi River.
I'm not sure how horseradish got its name. I always thought it had something to do with its pungent flavor being capable of knocking over a horse. Horseradish is a condiment capable of clearing sinus cavities and savored in sauces for seafood, pork and beef dishes.
Horseradish is a true perennial in the garden along with rhubarb and asparagus, but commercial growers produce it as an annual. According to Tony Bratsch, horticulture educator with University of Illinois Extension, home gardeners can get those large roots that are easier to peel and process by adapting the techniques that commercial growers use.
Start by planting horseradish in the fall or very early spring. Use root pieces (sets) that are finger width in diameter and about 12 to 18 inches long.
Till the garden and lay the sets horizontally, with the head (large end) slightly elevated. Cover the sets with six to eight inches of soil, forming a ridge one to two feet wide. One or two plants are usually plenty for the home gardener. After leaves appear, fertilize with compost or 10-10-10.
During the growing season, crowns with multiple shoots form above the ground, while the original set grows in diameter with many side roots forming underground. The goal is to grow the original set as large as possible. This can be achieved by either suckering or lifting.
Suckering is done by removing all but one or two leaf shoots at the head end as they develop. Lifting is simply digging through the ridge and gently lifting the crown end with a hoe to break roots forming at the crown; this forces side roots to form at the tail end. This should be done a couple of times during early and mid season, advises Bratsch. Both methods will result in greater swelling of the initial root, producing a large one to two pound main root at harvest. Once the top leaves are frozen in late fall, harvesting can begin.
Dig the large central root and as much of the secondary root system as possible. Be sure to save side roots for planting the next year's crop. Dug roots can be stored in the refrigerator for many months. Wrap them in plastic to conserve root moisture.
Horseradish can be harvested as needed throughout the winter and even into the spring. However, this method breaks side roots that grow into new plants, more plants than most gardeners would want.
Home gardeners can process horseradish by peeling and dicing the root pieces, and then grinding in a blender. A basic recipe is to fill a blender half full with diced horseradish, add a small amount of water and ice, and grind to desired consistency. To preserve and enhance the flavor, add two or three tablespoons of white vinegar (not cider vinegar) and a half-teaspoon of salt or one tablespoon of sugar. Vinegar stops the heat building enzyme activity caused by crushing. So for a milder sauce, add the vinegar immediately. For a hotter sauce, wait a few minutes after grinding before adding the vinegar. Place in clean jars. Don't fill the jars too full. Cover tightly. Store in the refrigerator or freezer. When you are really cold this winter, heat up your life with horseradish.