When Should Dead Sunflowers Be Chopped?

Deadheading sunflowers depends on your garden’s intentions and whether you plan to collect seeds or eat them. To deadhead, remove spent blooms before they set seeds for the longest vase life and prioritize the largest buds. Deadhead branching or multi-petaled type sunflowers more diligently to maximize their potential.

Start deadheading sunflowers when the flowers start to fade and the petals begin to wilt. If you are harvesting sunflowers to eat, cut off the flower head to eat the sunflower seeds. When sunflowers die, cut the stems off of the plant and discard them. If you want to save the seeds, carefully remove them from the flower head and store them in a paper.

Some signs to look out for when deciding to deadhead a sunflower include when the bloom has faded and looks spent, when the head is sagging over heavily, and when the seeds are forming and dropping into the soil. To prevent sunflowers from growing in the same garden next year, deadhead them to stop the seeds from forming and dropping into the soil.

Pruning common sunflowers in early to mid-spring is recommended to set the stage for a spectacular show. For perennials, consider a mid-summer trim to combat legginess. Deadhead sunflowers once they begin to lose their color and life prior to any seed production. Cut the stalk beneath the dead flower but above the first healthy leaf or new flower bud, making sure no new bud or growth is removed during the process.

A good rule of thumb is to prune them back to half of their size in late spring or early summer, then cut them back by about a third in June or July. In the fall, prune perennial sunflowers back to the ground.