Growing Your Own Horseradish

But last weekend, when we harvested the year-old roots of one plant, they were on the atomic side of hot.

“I can feel it burning all the way down,” my boyfriend, Rock, croaked, reaching into the fridge for his Gatorade. (The Rock gets heartburn from eating an orange.) “Now it’s a hot spot at the bottom of my stomach.”

My sinuses were clear for the first time in months. I couldn’t wait to mix huge dollops of this stuff with chili sauce to eat with steamed shrimp, or straight with rare roast beef.

And guess what? This root, when ground, produces isothiocyanates, chemical compounds that are studied for their anti-cancer properties.

“It would take about a tablespoon, on your steak, to give you that little anti-cancer shot,” said Mark E. Uchanski, an assistant professor at New Mexico State University in Las Cruces, who did his doctoral thesis at the University of Illinois at Urbana-Champaign on horseradish.

Horseradish (Armoracia rusticana) is in the brassica family, which includes turnips, kale, mustard greens, broccoli rabe, daikon radish and many other plants with varying degrees of pungency and a similar taste. Native to the temperate regions of Europe and Asia, it is an ancient herb.

“The Oracle at Delphi told Apollo that the radish was worth its weight in lead, the beet its weight in silver, and the horseradish its weight in gold,” Arthur O. Tucker and Thomas DeBaggio wrote in “The Big Book of Herbs” (Interweave Press, 2000), my bible for growing everything from hot peppers to patchouli.

The Romans carried horseradish to Europe as a medicinal herb and as a flavoring. It was cultivated in Egypt before the exodus of the Hebrew slaves around 1500 B.C., and is often the symbolic bitter herb at the Passover Seder.

By the 16th century, the pungent root was spreading throughout England. “The Herbal or General History of Plants,” by John Gerard, first published in 1597, describes its many uses, including as an aphrodisiac, a treatment for tuberculosis, a mustard plaster and a dewormer.

Pliny the Elder wrote about horseradish in his “Natural History,” an epic work of 37 volumes completed in A.D. 77, in which he observed that it healed sores, mange and ulcers.

The common name, according to Mr. Tucker and Mr. DeBaggio, probably evolved from the German “meerrettich,” which means sea-radish (the plant grows wild in coastal areas), which was misunderstood by the English, who associated “meer” with “mahre,” an old horse.

People haven’t changed: they just don’t pay attention.

Anyway, here’s what Rock and I have learned so far by growing this amazing root. Last April, Rock prepared the bed carefully, digging in plenty of compost and wood ash about a foot deep into the soil. Wood ash is rich in potassium and helps bring up the pH of our acidic soil to a more neutral 7, which is ideal for horseradish. (Horseradish will tolerate a pH range of 6 to 8, according to Johnny’s Selected Seeds, our mail-order supplier.) If you don’t have wood ash, you could use greensand, which is also rich in potassium, or lime.

After preparing the soil, Rock made a furrow with his hoe about six inches deep, and laid the root cuttings about 18 inches apart on a 45-degree slant in the soil. When they arrive from a supplier, cuttings have a thick, flat end that signifies the top of the mother root and a narrow end, cut on a slant, that indicates the bottom of the root. So if you set the thicker, flat end pointing up, you are mimicking the position of the original root.

Cover the root with about three inches of soil, pat it down and water well. That’s about it, except for keeping the weeds out and watering if it doesn’t rain. Rock mulched with clean straw to keep the weeds down and the moisture in.

By midsummer, those little sticks produced tall, broad leaves, shooting up in a rosette from the crown. They reminded me of dock weed, only much more ornamental. Earlier, around mid-May, the plant had produced an array of tall stems with tiny white flowers, which were kind of a bonus. The root, after all, is the prize.

We waited a year before harvesting, as the experts advise, which meant an early spring dig. The trick is digging the root before it leafs out, so as not to lose any pungency to top growth.