Stages of a Sunflower Plant

Germination and Emergence

• Once sunflower seeds are planted, they begin the germination and emergence stage. The stem emerges from the soil and grows into two leaves, also known cotyledons or true leaves. At this stage, the seeds thrive in temperatures above 46 degrees F. In temperate areas, seeds will usually complete this stage within 11 days.

Vegetation

• Once the sunflower plant has emerged from the soil, the true leaves continue to develop. When the sunflower has developed, with at least four true leaves of a minimum of 4 centimeters in length, it is in the vegetative stage. During this stage, the sunflower begins to form its flower head, which usually takes approximately 33 days.

Reproduction

• After the flower head has been formed, the germination stage is complete and reproduction begins. The flower bud gradually increases in size and height until it is approximately 2 centimeters above the nearest leaf. At this point, the flower head opens, or blooms. Then, pollination and seed production take place. When the flower wilts away, the seeds remain and turn deep black. They also lose moisture and can be harvested when the whole plant is dark brown, completing the plant's growth process.