• 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

Mammillaria magnimamma

Mexican pincushion

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
Mexican pincushion

© RHS

  • Other common names Mexican pincushion

  • Synonyms Dolichothele longimamma

  • Family Cactaceae

  • Genus Mammillaria are spiny cacti with spherical or columnar stems, often in clusters, with many prominent tubercles, and funnel-shaped flowers usually in a ring near the apex of the stem

  • Details M. magnimamma is a clump-forming perennial cactus. Tubby and spherical green stems are covered with tubercles (nodules), white spines and wool. Stems may reach 30cm in height. Small, funnel-shaped flowers, borne in spring and perhaps again in late summer, near the crowns are usually pink, but may also be red or cream

  • Plant range C Mexico

Characteristics

  • 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)

    H2

Colour

Sunlight

  • Full Sun

  • Aspect South-facing

  • Exposure Sheltered

Soil

  • Sand

    Sand

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Loam

  • pHNeutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Requires full sun and a well-drained potting medium. Minimum temperature of 5°C, so could be put outdoors in summer. See cacti and succulent cultivation

Propagation Propagate by potting up offsets or by propagate by seed in spring or summer

Suggested planting locations and garden types Low Maintenance Drought Resistant Patio & Container Plants City & Courtyard Gardens Architectural

How to care

Pruning None required

Pests May be subject to the usual heated glasshouse pests such as mealybugs

Diseases Sharp drainage and keeping completely dry in winter will prevent rots

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