DIY Network

Horseradish Overview Joe Lamp'l discusses the unique properties that make planting horseradish so interesting. From "Fresh from the Garden" episode DFFG-311

Joe Lamp'l prepares an out-of-the-way garden bed for horseradish roots (and explains the necessity of placing them away from the rest of the garden).

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Horseradish is a very fast-growing hardy perennial. Best known in the U. S. for its spicy flavor, it was originally grown as a medicinal or herbal cure for digestive and respiratory problems. Although gardening experts can't agree on exactly where horseradish got its start, northern Europe is the likely birthplace of this fiery root vegetable.

Most of us are used to getting horseradish prepared or grated in a jar; if you like it this way, you'll be blown away by the flavor of fresh horseradish. You can buy fresh horseradish roots in the market's produce section. It has a tough whitish-brown outer skin (figure A); when you cut into it, the flesh is white and fibrous (figure B). Inside is where all the heat is, so be careful!

Figure A

Figure B

Horseradish has some drawbacks that you should know about before you plant it. It's one of the most invasive and prolific vegetables you can grow: even the smallest piece of a root left in the ground will shoot right back up. This is not a plant to grow in the same bed as other vegetables; you need to put it in a corner of the garden where you won't till or turn the soil. If you don't have a spot like that, then put it in a large pot to keep it contained.

Pick an out-of-the-way location, away from the rest of the garden, to plant horseradish. Horseradish likes the same healthy soil that all vegetables like--well-turned loose dirt, organic materials and the works--but doesn't need the extra attention that other vegetables need.

Figure C

Horseradish needs loose soil so that its root can grow straight down. Hard soil, like clay, can make the root bend or even cluster. Turn the soil 8" to 12" with a garden fork (figure C), breaking up any clods you see; this will keep the roots on the straight and narrow. If the soil is clay, add some sand to make the dirt drain better and to give the horseradish roots lighter soil to push through.

It's a good habit to start new planting beds with a dose of balanced fertilizer. A 10-10-10 mixture has an equal amount of nitrogen, potassium and phosphorus. Even though the horseradish would do fine without it, the seedlings will get off to a better start with a little fertilizer. Be careful, though, that you don't add too much nitrogen: like other roots crops, horseradish will develop too many leaves and not enough roots if it has too much nitrogen. Work the fertilizer into the soil, down into the root zone, which is 4" to 8" below the surface. Do not, however, add any manure to the horseradish bed: even though it's great for most vegetables, it's too high in nitrogen for horseradish.

Planting horseradish roots is quite simple.

1. Make sure you have the root turned the right way: the pointed end goes down and the knobby end goes up. If the seedlings have any leaves, you can tell right away which side us up.

2. Make a hole that's about 5" to 8" deep. To plant the horseradish, just lay it at an angle in the hole with the root end down (figure D).

3. Once the horseradish roots are in the ground, cover them with dirt and lightly tamp it down (figure E). If there are leaves, make sure they're just under or even with the surface; the leaves will pop through the dirt if the roots aren't planted too deeply. Water the seedlings until the ground is wet but not flooding (figure F). If the soil gets dry, water as needed to keep the roots fresh and healthy until they get a little bigger.

Figure D

Figure E

Figure F

4. If it's still cold out, a layer of straw will help keep the soil warm (figure G). Horseradishes are hardy perennials that can be planted early in the spring, but if you wait until after the last frost, the plants will take off quickly. They'll overwinter in their spot and grow for years and years (probably longer than you'd imagine). Although mulch helps keep the soil warm and discourages weeds, take care not to put down a thick layer that could hamper germination.

Safety note: Wear gloves when planting and handling horseradish (figure H): it's extremely spicy and can irritate eyes and skin.

Figure G

Figure H