Here's why:
* Warm weather: Sunflowers thrive in warm temperatures, and spring provides the ideal conditions for germination and growth.
* Longer days: Sunflowers need plenty of sunlight, and the longer days of spring and summer provide the optimal amount.
* Soil moisture: Spring soil is typically moist, which is crucial for seed germination.
However, depending on your location's climate, you might be able to plant sunflowers in early summer as well.
Important note: The best time to plant sunflowers varies depending on your specific climate. Check your local gardening resources or a planting calendar for the best planting times in your area.