Helianthus, from the common name “Sunflower” as the most popular annual species. Helianthus Annus are heat-tolerant, resistant to pest and simply beautiful.

Planting Guide

Size/ Plant Habit: 6 – 20 inches tall, single stem/ annual

  • Big Smile: Early blooming, dwarf plant, nearly day length neutral (can be produced for pots year round)
  • F1 Smiley: Height under short days: 5 – 8 inches tall, under long days: 13 – 16” / annual

Market Use:

  • Big Smile: Bedding, summer sales, pot sales, combination planters.
  • F1 Smiley: Pot crop, patio pot, mixed container


Cultural Recommendations

Sowing: Well suited to sow directly to nal container, but large plug sizes (200 cell tray minimum) can be used
Finish Container: 4½ to 6”, gallon or multiples in larger containers

Seedling Stage

  • Germination: Emergence 5 – 10 days/68 – 72°F / cover seed
  • Seedling Finish Time: If started in plugs, be sure to transplant before plants become stressed or excessively stretched, generally plants are ready for transplanting around 21 – 25 days


  • Transplant: Direct sow, if sown in plugs transplant around 21 – 25 days
  • Days to Flower After Sowing: 50-55 days
  • Temperature: 75 – 85°F day / 65 – 70°F night
  • EC: 1.75-3.0 mS/cm (pour thru method)
  • pH: 6. 0-6.5
  • Common Problems: Pythium root rot is a problem especially during cool, moist weather


  • Avoid over watering the sunflower and allow the plants to dry moderately.
  • Keep plants fed enough to maintain green cotyledons up to flowering. Watch for iron deficiency when pH exceeds 6.8.
  • Nutritional and/or water stress early in the culture of Helianthus (especially in plug trays) can cause premature budding and lower finish quality

Related Flowers

Ramgo International
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