Helianthus
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
Characteristics:
- 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
Finishing
- 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
NOTES:
- 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
