Edible plant · roots bulbs

Horseradish

Armoracia rusticana

Also known asMountain radish · Pepperroot · Meerrettich · Raifort

beginner cool-season continuous

Use in garden planner

Days to harvest

180–365

Yield / plant

0.5kg

Spacing

60 cm

Daily light

15–25DLI

Environment

The bounded range this crop tolerates.

Temperature

5152535

5–28°C

45.578.5

6–7.5

EC (hydro)

01234

1.4–2 mS/cm

Daily light

5152535

15–25 mol/m²/d

✓Continuous harvest

Climate and zones

USDA zones: 3–9 (winter low around -40°C)
Frost: very hardy (survives deep cold)
Season: cool (spring/fall)

✓Outdoor year-round (in zone)

✓Outdoor in growing season

·Unheated greenhouse / hoop

·Heated greenhouse

·Indoor (heated home)

·Indoor hydroponics + grow lights

Growing systems

Root mass: very heavy. Thin-channel systems can't hold this crop.

·Deep water culture (rafts)

·NFT channels

·Vertical / aeroponic tower

·Drip / Dutch buckets

·Media bed (ebb and flow)

·Wicking bed

✓Soil bed

Growing media

Medium	pH effect	Retention	Bacterial surface
Soil-based mix (Potting soil)	varies	high	high

Nutrient demand by stage

NPK ratios are relative weights. EC targets shift through the plant's life.

Stage	N	P	K	EC (mS/cm)
seedling	2	1	1	1
vegetative	2	1	2	1.6

Aquaponics suitability

Not recommended

Fish waste alone doesn't supply enough of what this crop demands. Grows in hybrid systems with supplemental dosing, but expect active management.

Care notes

A vigorous perennial root crop for outdoor aquaponics media beds. Very deep growing medium (30 cm minimum, ideally 50+) for the taproot. EC 1.5-2.5 mS/cm. pH 6.0-7.5. Temperature: cold-hardy perennial (USDA zones 3-9); grows actively at 15–25°C. Full sun to partial shade (DLI 14-20 mol/m2/day). Propagation by root cuttings (pencil-thick root pieces, 15–20 cm long, planted at 45 degrees). The plant is invasive: any piece of root left in the ground regrows, and the plant spreads aggressively. In contained media beds, this is manageable; in open ground, it can become a permanent weed. Harvest roots in fall after the first frost (cold improves flavor). Dig the entire root mass, replant a few root pieces for next year, and process the rest. Grate the root immediately before serving (the pungency fades quickly once exposed to air) or mix with white vinegar within 5 minutes of grating to preserve the heat. The flavor of freshly grated homegrown horseradish is dramatically stronger than store-bought prepared horseradish, which has mellowed during months of storage.

Notable varieties

Cultivar	Type	Days	Notes
Common Horseradish	heirloom	240	The standard variety, sold simply as 'horseradish.' Reliable, vigorous, the variety most home garden horseradish is.
Big Top Western	open pollinated	240	Improved variety with larger straighter roots, easier to dig. The variety most US commercial horseradish production uses.