• 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

Euphorbia horrida

African milk barrel

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
African milk barrel

© � RHS 1965

  • Other common names African milk barrel

  • Genus Euphorbia can be annuals, perennials, shrubs or succulents, with milky sap and small flowers held within cupped, often colourful bracts

  • Family Euphorbiaceae / Euphorbiaceae

  • Details E. horrida is a cactus-like shrub with erect, ridged stems bearing long spines and solitary green flowers

  • Plant range S Africa (Cape)

Characteristics

  • Foliage Evergreen

  • Habit Clump-forming

  • Toxicity All parts are highly toxic by ingestion

  • 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)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H2

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or East-facing or North-facing

  • Exposure Sheltered

Soil

  • Chalk

    Loam

  • Chalk

    Sand

  • MoistureWell-drained

  • SoilLoam, Sand

  • pHNeutral, Alkaline, Acid

Size

  • Ultimate height

    1-1.5 metres

  • Ultimate spread

    0.1-0.5 metres

  • Time to ultimate height

    10-20 years

How to grow

Cultivation Grow under glass in a loam-based potting compost with sharp sand in full light with good ventilation. Water sparingly when in growth keep dry in winter. In the growing season feed a low nitrogen liquid fertiliser 2 or 3 times

Propagation Propagate by seed sown at 15 - 18�C in early spring or stem in spring or early summer. Separate offsets in spring

Suggested planting locations and garden types Low Maintenance Patio & Container Plants

How to care

Pruning No pruning required

Pests May be attacked by mealybugs

Diseases Generally disease free

Advertise here

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now