Thompson & Morgan Sunflower Giant Yellow - 50 Seeds

Thompson & Morgan Sunflower Giant Yellow typically grows to a height ranging from 1.8 to 2.7 meters (approximately 6 to 9 feet).

It is best to sow these seeds directly outdoors after the last frost has passed in your area, typically in late spring.

Yes, due to their significant height, staking is often recommended to support the plants and prevent them from falling over, especially in windy conditions.

They prefer fertile, well-drained soil. Adding compost before planting can improve soil quality and performance.

Sunflowers require full sun, meaning they need at least 6 to 8 hours of direct sunlight per day to grow and flower best.

While possible, their large size makes them best suited for in-ground planting. If using pots, choose very large, sturdy containers and ensure consistent watering and feeding.

These sunflowers typically bloom from July through September, providing color for a significant part of the summer and early autumn.

Ensure seeds are planted at the correct depth, soil is kept consistently moist, and the temperature is adequate (above 10°C). Check seed viability if very old.

Verify they are receiving enough sunlight (minimum 6-8 hours daily) and that the soil is well-drained. Poor soil quality might require fertilizing.

Use slug pellets, beer traps, or apply barriers like crushed eggshells around young plants.

Install stakes or supports early in the plant's growth, especially in exposed or windy locations.

Ensure adequate sunlight and water. Extreme weather conditions or nutrient deficiencies can also affect flower development.