Giant Sunflower plants that can grow up to 3m in height with flowers that can span up to 30cm across. The stems are thick and because the plants grow so tall, it is advisable to support them, especially when they are in flower.
Garden and Soil Benefits:
- Soil Aeration: Most people forget that sunflowers have incredibly strong, deep root systems that help break up soil structure after the season ends.
Growing Giant Sunflower
Indoor Sowing: Not Recommended.
Direct Sowing: Late Spring and Early Summer.
- To grow the largest sunflowers, it is essential to direct sow seed directly into the garden, rather than start them in pots of any kind.
- Sunflowers need full sun and they need on average 6-8 hours of direct sunlight per day – the more the better if you are trying to grow them to their maximum potential.
- They grow best at temperatures between 18–33ºC.
- Plant the seeds in holes or trenches one seed 2.5 cm deep, or 5 cm if the soil is loose and sandy.
- Plant seeds at least 30 cm from each other, to give each one enough space to grow.
- Cover the seeds with soil after planting.
- If the soil is kept moist, seedlings will appear within 5-10 days.
- The plants need to be staked and supported, especially when in flower.














