• 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

Tithonia rotundifolia

Mexican sunflower

Mexican sunflower

© Mike L. Grant 2000

  • Other common names Mexican sunflower
    Mexican marigold

    goldflower of the Incas

    see more
  • Synonyms Tithonia speciosa

  • Family Asteraceae

  • Genus Tithonia can be annuals, perennials or shrubs, with simple or lobed leaves and long-stemmed, solitary, daisy-like flower-heads in late summer and autumn

  • Details T. rotundifolia is a large, branching annual to 2m, with large, broadly ovate leaves and vivid orange, daisy-like flowers 8cm across

Characteristics

  • Foliage Deciduous

  • 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)

    H2

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • Sand

    Sand

  • MoistureWell-drained

  • SoilLoam, Sand

  • pHNeutral, Acid, Alkaline

Size

  • Ultimate height 1.5-2.5 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Grow in well-drained, moderately fertile soil in full sun with shelter from strong winds. Water freely in dry weather. Cool overcast weather results in poor growth

Propagation Propagate by seed sown in gentle heat in spring

Suggested planting locations and garden types Flower borders and beds Cut Flowers Cottage & Informal Garden Gravel Garden

How to care

Pruning Cut back after flowering

Pests Young foliage may be attacked by slugs and snails

Diseases Generally disease free

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