Perennials
Horseradish
Root cuttings in Apr; vigorous, contain it.
- Outside
- Plant root cuttings in Apr
- Where
- In ground boxed in, bin, or deep bag
- Sun
- Full sun to part shade
- Water
- Only in a real dry spell; mulch holds the rest
- Harvest
- Roots late fall after frost
Care
- Water
- Horseradish is tough and nearly self-sufficient. Once the roots take, the bed runs on rain and wants a soak only in a real dry stretch. A compost or leaf mulch over the crowns keeps the soil cool and damp and stretches those gaps further.
- Sow
- Plant pencil-thick root cuttings in April, 2 to 3 inches deep and a foot apart, cut square on top and slanted on the bottom so up stays obvious. Pen it in against its own spread, a barriered bed or a sunken bin, or a stray scrap colonizes the plot.
- Feed
- No feeding schedule to keep. A shovel of compost worked deep into the bed at planting, then a compost or leaf mulch topdressed each spring, is the whole program. Rich, deep, loose soil grows a straight root, and that is most of the job.
- Ready
- Wait for hard frost to sweeten the root, then lift from mid October until the ground locks up. Drive a fork down one side, lever the roots free, keep the long main ones, and set aside an 8 inch cutting to restart next spring.
- Trouble
- Shot-hole flea beetle damage on the leaves: cosmetic only, since the root is untouched; cover or hand-pick if it turns to lace. The real trouble is escape: every fragment left at harvest resprouts, so dig clean and keep it boxed in, or it owns the plot.
In a bag?
- Yes
- Up to a 10–15 gal bag.
- Water
- A bag dries far faster than open ground. Water in a dry stretch, 60 to 90 sec on the shower dial until it runs from the seams.
- Sow
- Use a deep 10 to 15 gal bag so the root has length to run, one crown to a bag; the bag itself is the containment, no barrier needed.
A contained brute: horseradish penned into a bin, a barriered bed, or a deep bag because in open ground it would annex the yard. Roots dug after October frost grind into a sauce with real menace.
Growing
Plant root cuttings in April, angled, buds up, penned into a barriered bed, a buried bin, or a deep bag; containment is not optional, since any inch of root left behind becomes a new colony. Full sun to part shade, water in drought, and otherwise ignore it while the big leaves do their work. Frost sharpens the root, so dig from mid October into November. Fork down one side, or tip a bag right out, take the main roots, and replant one cutting to restart next year's supply.
Varieties
Sets are usually sold unnamed and grow fine; Maliner Kren is the strain most often behind the label.
Pests
Flea beetles and imported cabbageworms both find the leaves, horseradish being a brassica under all that attitude, and neither touches the root; the damage stays cosmetic. Nothing else volunteers to eat it.
In the kitchen
Grate outdoors or regret it; vinegar added immediately keeps the heat polite, while waiting three minutes sharpens it considerably. A jar in the fridge covers roast beef, cocktail sauce, and Bloody Marys until spring.