• 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

Washingtonia robusta

southern washingtonia

  • Other common names southern washingtonia
    Mexican washingtonia

    Mexican fan palm
    thread palm

    see more
  • Family Arecaceae

  • Genus Washingtonia are large evergreen palms with stout solitary trunks bearing long-stalked, rounded leaves palmately divided into linear segments, and large, arching panicles of flowers, followed by small, berry-like black fruits

  • Details

    W. robusta is a tall, fast-growing, evergreen palm with a slender trunk that swells considerably at the base on mature specimens. Large fan-shaped leaves with leaflets up to 1.5m long are borne on spine-edged petioles to 1m long. Long sprays of small white flowers are borne on hanging, branched stems to 3m long and followed by dark brown fruits

  • Plant range Mexico


  • Foliage Evergreen

  • 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)




  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Sheltered


  • Loam


  • MoistureWell-drained

  • SoilLoam

  • pHAcid, Neutral


  • Ultimate height Higher than 12 metres

  • Ultimate spread 2.5-4 metres

  • Time to ultimate height 10-20 years

How to grow

Cultivation Grow under glass in loam-based compost with added leaf mould and sharp sand, in full light. Water moderately, provide moderate humidity when in growth and apply a liquid fertiliser monthly during the summer. Water sparingly in winter . See palm cultivation indoors

Propagation Propagate by seed

Suggested planting locations and garden types Architectural Patio & Container Plants

How to care

Pruning Needs no regular pruning, but dead leaves may be removed by cutting close to the leaf base leaving stubs to create a neat pattern

Pests Glasshouse red spider mite and scale insects may be troublesome

Diseases Generally disease free

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