Horseradish

Armoracia rusticana

Family Brassicaceae

PerennialZones 3-9

Botanical illustration of Horseradish

Real horseradish — dug after the first hard frost and grated fresh — has a clean, sinus-clearing fire the jarred stuff loses within weeks. One established plant supplies a year of cocktail sauce, roast-beef Sundays, and homemade preparations no store shelf can touch.

Hardy through zones 3-9 and vigorous to a fault, it asks only for a bed of its own — give it a dedicated corner and it will feed you for decades. Bees work the summer flowers; you get the October dig. Set aside that corner this fall.

⚠ Spreads aggressivelyHorseradish spreads vigorously and regrows from bits of root, so it's very hard to fully remove once established — give it a contained bed or a spot where it can roam freely, and edge it every year.

Where to buy horseradish — 1 nursery compared

  • Full Sun to Part Shade
  • Moderate water
  • Fast growth
  • Excellent edible
  • Attracts bees
Horseradish — a print from the Plant Library collection

From the print shop

Growing horseradish? Hang it.

Our Plant Library collection carries horseradish — Armoracia rusticana, print Nº 238, “Horseradish.”

526 designsfrom $12.99white or black backgroundmatte poster, unframed

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Will it fruit where you are?

Enter your ZIP — we look up your USDA hardiness zone (2023 map) and check it against what horseradish actually needs.

Hardy inZones 3-9

Horseradish · Common problems

Common horseradish problems

Pests, diseases and weather to keep an eye on.

Pests

2 problems on file

Diseases

1 problem on file

Horseradish · Growing & propagation

Growing horseradish

Light, water, soil, propagation and the season’s jobs.
What it needsThe details
Light
Full Sun to Part Shade
Water
Moderate

Wants steady moisture for fat roots

Soil
Deep, Rich, Loose · pH 6.0 - 7.0
Fertilizer
Compost in spring

Little else.

Pruning
None — None.
Spacing
24-30 inches

How to plant & propagate horseradish

Propagate
Division or seed

Horseradish · Seasonal care & spray guidance

The horseradish growing playbook

Field-tested instructions for every job horseradish asks of you, compiled from university extension guidance — in the order the season brings them.

As growth begins

early spring

2 jobs
SowingIn spring

Plant root sets as soon as the soil is workable

Spade or rototill 8 to 10 inches deep and work in well-decayed compost. Set 8 to 10 inch root cuttings a foot apart, angled at about 45 degrees with the fat end up, and cover the top with 2 to 3 inches of soil. Sink a bottomless tub or a 12 inch wide section of PVC around the planting if you do not want it to run. Horseradish makes its root growth in the long cool stretch before summer, so a set that goes in late never sizes up. It also spreads by underground shoots and out-competes almost everything near it, which is why growers confine it from day one rather than fight it later.

FeedingIn spring

Side-dress nitrogen twice in the first two months

Work in a complete garden fertilizer such as 10-10-10 at one pound per 100 square feet at planting, then side-dress about a teaspoon of 21-0-0 per plant at 4 weeks and again at 8 weeks after the sets go in. Follow a soil test where you have one. Horseradish is pulling a large leaf canopy and a thick storage root out of the same season, and the nitrogen it needs for that is spent early. Feeding twice in the first two months carries the canopy that fills the root.

Through summer

the growing season

3 jobs
WateringIn summer

One deep soak a week through the growing season

Give 1 to 2 inches of water once a week, enough to wet the soil 18 to 24 inches down. Water deeply and infrequently rather than in daily sips. The harvestable root sits a foot and a half or more below the surface, and it only chases water that reaches it. Both drought and waterlogging show up directly in the eating quality, turning the root woody or bland.

ThinningIn summer

Lift and strip the roots twice for one straight root

When the largest leaves reach 8 to 10 inches, ease the soil away from the upper root without pulling the plant, rub off every small side root along the crown and sides of the main root, and cut back to the single best crown of leaves. Firm the soil back and repeat the whole operation about six weeks later. Left alone, every side root and every extra crown becomes its own branch, and you dig a tangled mat instead of a root you can grate. Stripping forces the plant to put the season's growth into one main root.

What to watch forIn summer

Watch young plants for flea beetles, then mostly let them be

Check new plantings for the shot-hole peppering of horseradish flea beetles and for imported cabbageworm larvae chewing the leaves. Treatment is warranted only on young plants carrying more than about five beetles each, or where 10 to 30 percent of the leaves on seedlings have dropped. Once plants are past the 4 to 5 leaf stage, damage is generally cosmetic and needs nothing. A floating row cover over young plants excludes the beetles without any spray. Horseradish flea beetles feed on the foliage and not on the root you are actually harvesting, and an established plant carries far more leaf than it needs. Spraying a root crop for cosmetic leaf damage buys nothing.

After harvest

autumn, and putting it to bed

2 jobs
DividingIn autumn

Save next year's sets and clear every root fragment

As you dig, cut the straight pencil-thick side roots into 8 to 10 inch sets for next spring, bundle them, and bury them in moist sand at 32 to 40 degrees in a root cellar or basement. Chase down and lift every remaining root piece in the bed, and move the planting to fresh ground every three or four years. Any fragment left behind sprouts next spring, which is how a tidy bed becomes a permanent one you cannot dig out. Rotating the site and replanting only clean, disease-free cuttings is the whole defense against the root rots that build up in horseradish ground.

HarvestingIn autumn

Dig after frost has killed the tops

Wait until several frosts have taken the leaves down and the ground is close to freezing, then dig a trench 12 to 24 inches deep along one side of the row and lever the roots out from the opposite side with a spading fork. Expect to need a full 150 day season before the roots are worth digging. Horseradish makes its greatest root growth in late summer and early fall, so every week you wait past Labor Day is adding weight. Frost kills the canopy but the root below is unharmed and at its best flavor.

Horseradish · Calculators & field guides

A little help in the garden.

Calculators for the figures. Field guides for the hands-on work.

Horseradish · Yearly calendar

The horseradish year, month by month

What horseradish asks for, month by month.

Jan

No calendar activity is listed for this month.

MonthJanFebMarAprMayJunJulAugSepOctNovDec
Bloom
Harvest

BloomJune

HarvestOctober to November

What each band means

  • Bloom — flowers open — pollinators working, frost on blossoms is the danger.
  • Harvest — picking time — check ripeness every few days.

These are the species' typical months — expect them a few weeks earlier in warm zones and later in cold ones. Watch the plant, not just the calendar.

Horseradish · Ecology & uses

Ecology & uses

What it does for the garden, and what it is grown for.
Botanical illustration of Horseradish

Armoracia rusticana

Horseradish in the garden system

  • Root layer perennial
  • Dynamic accumulator
Attracts
Bees
Moisture
Facultative / average
Deer
Browsed

Protect young plants

Origin
Introduced

What horseradish is grown for

✓ Commonly eatenSafe in food amounts

Use
Condiment
Traditional use
Medicinal
Use
Companion
Edible value
4/5

Harvesting & storing horseradish

October - November, after frost.

Edibility, identification, and traditional-use notes here are general reference — not medical or veterinary advice, and not a claim that any plant treats or prevents anything. Medicinal ratings record how strongly a plant features in herbal tradition, nothing more. Never eat or dose a plant you have not positively identified. More on how to use this library.

Horseradish · Varieties & cultivars

Best horseradish varieties & cultivars

There are far more than these — the ones below are the named varieties of horseradish people actually plant.

Named varieties of horseradish differ in winter-chill needs, ripening time, hardiness, and whether they set fruit on their own — pick one that fits your climate.

7 varieties

Common

Also known as Maliner Kren

Ripens
October - November, after frost
Zones
3-9
Disease
Susceptible to white rust and turnip mosaic virus
Size
Large, vigorous; largest roots of the common types

Superior eating quality, the benchmark for pungency — The broad crinkled-leaf type long preferred for commercial production and the standard against which other horseradish is judged. Its weakness is disease, not flavor. Days to maturity reflects the 150 day season Utah State gives for horseradish generally.

Where to buy ‘Common’

Story Thyme Farms may earn a small commission from these links, at no cost to you — it never changes what we recommend.

Sources & plant identity

Know what you’re growing.
See where the knowledge comes from.

Botanical illustration of Horseradish

Horseradish

Armoracia rusticana

The plant, at a glance.

Botanical name
Armoracia rusticana
Plant family
Brassicaceae
Growth habit
Perennial
Origin
Introduced
USDA plant symbol
ARRU4
Invasive risk
Spreads aggressively
Every garden is different.

Hardiness, size and timing vary with your cultivar, soil and climate.

Rooted in research.

University extension research, brought together with hands-on growing experience at Story Thyme Farms.

Explore Horseradish’s sources6 reference links
for Horseradish

Research from these sources

Publisher marks identify sources, not sponsorship or endorsement.

Questions

Horseradish questions, answered straight.

Is horseradish safe for kids and pets?

Horseradish is commonly eaten and isn't considered toxic, but "commonly eaten" isn't a guarantee for any particular person or animal — allergies, quantity, and which part you eat all matter. One caveat on this one: Safe in food amounts. Never eat a plant you haven't positively identified, and check with a vet before letting pets or livestock graze anything new.

When do you harvest horseradish?

October - November, after frost.

How do you propagate horseradish?

Division or seed.

Is horseradish invasive?

It can be an aggressive spreader — give it room or a barrier, and check your state's invasive-species list before planting.

Elsewhere

Where horseradish sits in the library.

Where horseradish sits in the library

Grows in the same world