• 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

Kalanchoe daigremontiana

Mexican hat plant

Mexican hat plant

© RHS 1999

  • Other common names Mexican hat plant
    devil's backbone

    flopper

    see more
  • Family Crassulaceae

  • Genus Kalanchoe can be annuals, biennials, perennials, shrubs or trees, with succulent, simple or pinnately lobed foliage and tubular or bell-shaped flowers with four lobes

  • Details K. daigremontiana is an upright succulent perennial with trinagular-lance-shaped, grey-green leaves, often spotted with brown, and with a row of plantlets on each edge; pendent, tubular greyish pink flowers 2cm long open in winter

  • Plant range Madagascar

Characteristics

  • Foliage Evergreen

  • Habit Bushy

  • 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)

    H1B

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or East-facing

  • Exposure Sheltered

Soil

  • Sand

    Sand

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Loam

  • 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 under glass in a loam-based potting compost with additional perlite, sharp sand or grit in full light with good ventilation. Water moderately throughout the year but more sparingly in winter. In the growing season feed a balanced liquid fertiliser 2 or 3 times

Propagation Propagate by seed sown at 19 - 21ºC in early spring or by offsets

Suggested planting locations and garden types Patio & Container Plants

How to care

Pruning No pruning required

Pests May be attacked by mealybugs and aphids

Diseases Powdery mildews and a rust may be a problem

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