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Giant Sunflower

Scientific name

Helianthus giganteus


Giant Sunflower, also called Tall Sunflower or Swamp Sunflower, is a perennial wildflower species that grows up to 3 m in height. The tall stem is green to reddish purple in colour and covered in hairs. Giant Sunflower leaves are typically alternate, lanceolate to elliptic, rough-textured on the upper surface, with soft white hairs on the lower surface. Numerous flowers develop at the top of the plant, with each flower having 10-20 bright yellow petals and a darker yellow center disk. Giant Sunflower is beneficial to native pollinator species, including bumblebees and butterflies.

Planting conditions

Giant Sunflower prefers moist to wet environments in full sun. It does best in a well-drained sandy soil and is adaptable to all soil Ph levels. Giant Sunflower grows naturally in swamps, marshes, and moist woods.


  • Plant height:
    • Max 3m
    • Any
  • Moisture level:
    • Moist
    • Wet
    • Flood Tolerant
  • Light conditions:
    • Full sun
  • Soil type:
    • Sandy
  • pH:
    • Acidic
    • Basic
    • Normal
  • Depth:
    • Wildflower
  • Plant type:
    • Wildflower
  • Height:
    • 3 m
  • Spread:
    • 1 m