A perennial, cold hardy crop, horseradish is easy to grow in sun or partial shade, and quickly makes itself at home in gardens. Set out roots a few weeks before your last frost date, in any fertile, well drained soil. Grating horseradish crushes the cells of the root, releasing the volatile oils (isothiocyanates), which gives horseradish its heat. Adding vinegar stops the enzymatic reaction. The longer you wait to add the vinegar, the hotter your prepared horseradish will be.