• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Armoracia rusticana

horseradish

horseradish

© RHS 2002

  • Other common names horseradish
    pepper root

    pepper turnip
    red cole
    horseradish

    see more
  • Synonyms Cochlearia armoracia

  • Family Brassicaceae

  • Genus Armoracia are robust upright tap-rooted perennials with simple or pinnately lobed leaves, and small white, 4-petalled flowers in terminal panicles or racemes

  • Details A. rusticana is a vigorous rhizomatous perennial with fleshy, pungently aromatic tap-roots, large, dock-like bright green leaves and panicles of small, white flowers in early summer

  • Plant range SE Europe

Characteristics

  • Foliage Deciduous

  • Habit Columnar/Upright

  • Hardiness

    Hardiness ratings

    All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

    • H1a - Under glass all year (>15C)
    • H1b - Can be grown outside in the summer (10 - 15)
    • H1c - Can be grown outside in the summer (5 - 10)
    • H2 - Tolerant of low temperatures, but not surviving being frozen (1 to 5)
    • H3 - Hardy in coastal and relatively mild parts of the UK (-5 to 1)
    • H4 - Hardy through most of the UK (-10 to -5)
    • H5 - Hardy in most places throughout the UK even in severe winters (-15 to -10)
    • H6 - Hardy in all of UK and northern Europe (-20 to -15)
    • H7 - Hardy in the severest European continental climates (< -20)

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

  • Aspect South-facing or West-facing

  • Exposure Sheltered or Exposed

Soil

  • Loam

    Loam

  • Chalk

    Chalk

  • Sand

    Sand

  • Clay

    Clay

  • MoistureWell-drained

  • SoilLoam, Chalk, Sand, Clay

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in light, fertile and deep, moist but well-drained soil in full sun. Water freely during the growing season. Can be invasive

Propagation Propagate by seed or by division in winter

Suggested planting locations and garden types Wildlife Gardens

How to care

Pruning Cut back after flowering

Pests Generally pest free

Diseases May suffer from club root

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