Factors Affecting Seed Germination of a Sunflower

Temperature

• "Optimum temperatures for growth are 70 to 78° Fahrenheit, but a wider range of temperatures (64 to 91°F) show little effect," according to Purdue University's Alternative Field Crops Manual. Sunflower seeds have been known to germinate at temperatures as low as 39° Fahrenheit.

Moisture

• Well-draining soil that holds some moisture is best for sunflower germination. Sunflower seeds grow best in fertile loamy soil that acts like a sponge. Sunflower sprouts will succumb to mold and fungus if conditions are too wet. Standing water will kill newly sprouted sunflower seeds.

Soil

• Plant sunflower seeds in soils that contain compost and nitrogen to help the sprouts achieve adult status in a relatively short time. Lack of soil nutrients will lead to stringy sprouts with yellow leaves, and the sunflowers will never reach their optimum level of growth.