Horseradish is a hardy perennial root grown for its pungent flavor. Utah State University Extension says 4 to 6 plants are enough for the average family garden. Any root left in the ground can regrow, so many gardeners contain the plants.
Horseradish at a glance
| Type | Vegetable |
|---|---|
| Season | Perennial |
| Sun | Full sun |
| Plant spacing | 12 in |
| Row spacing | 30 in |
| Per square foot | 1 |
| Seed depth | 1.5 in |
| Days to maturity | Harvest in autumn after several frosts |
| How to start | Plant in late March or early April. |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant horseradish
Plant in late March or early April. Use crown cuttings (recommended for short growing seasons) or root cuttings. Check your frost dates.
How to plant horseradish
- Crowns: plant 1 to 2 inches below the surface at a 45-degree angle after the wounds heal for several days.
- Root cuttings: pencil-sized root pieces, planted 2 to 3 inches deep with the square end higher than the angled end, 1 foot apart.
- Soil: well-drained, high in organic matter and fertile, pH 6.0 to 7.5. Use the plant spacing calculator.
Caring for horseradish
Few pests or diseases affect horseradish, but root rot is common if plants are overwatered; see the garden watering calculator.
Companion plants
| Grow nearby | Potatoes and other root vegetables in separate beds |
|---|---|
| Keep apart | Beds you plan to rotate |
Small leftover roots can become weeds, so dig all roots at harvest. Some gardeners grow it in buried pots or 12 by 24 inch PVC pipes. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Spreading | Horseradish returning in the bed | Leftover roots regrow; dig them all at harvest or contain the plants. |
| Root rot | Rotting roots in wet soil | Common if plants are overwatered; improve drainage. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Harvest in autumn, after several frosts have improved the flavor. In regions with 150-day growing seasons, it can be harvested at the end of the first year. Store intact roots in moist sand or sawdust in a dark root cellar, or in a plastic bag with moist sand in the refrigerator; they keep their flavor for up to 3 months. Save side roots for spring planting.
Plan your horseradish
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant horseradish plants?
Space horseradish plants 12 inches apart in rows 30 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant horseradish roots?
Plant crowns 1 to 2 inches deep or root cuttings 2 to 3 inches deep, 1 foot apart.
How long do horseradish plants take to grow?
Harvest in autumn after several frosts, or at the end of the first year in regions with 150-day seasons.
How much water do horseradish plants need?
About 1 inch of water a week, from rain and watering combined. Avoid overwatering; root rot is common in wet soil.
How many horseradish plants do I need?
Utah State says 4 to 6 plants meet an average family's needs.
How do I stop horseradish spreading?
Dig all roots at harvest, or grow it in buried pots or 12 by 24 inch PVC pipes.
How long does horseradish keep?
Intact roots keep their flavor for up to 3 months in moist sand in the fridge or a root cellar.