False sunflowers (Heliopsis) are sun-loving, butterfly magnets that provide bright yellow, 2-inch (5 cm.) flowers reliably from midsummer to early autumn. Heliopsis requires very little maintenance, but these impressive plants benefit from regular trimming and cutting back, as false sunflowers reach heights of 3 to 6 feet (1-2 m.). Read on to learn more about false sunflower pruning.
How Do You Cut Back False Sunflowers?
Cutting back false sunflowers is an easy process, though it helps to trim false sunflowers in stages to keep the plants looking their best throughout the growing season. For example, pinch the growing tips of young plants in spring to create full, bushy plants, then keep the plant deadheaded throughout the blooming season to prevent false sunflowers from going to seed prematurely.
Cut the plants back by about half if they begin to look floppy or scraggly in early summer. The rejuvenated plant will reward you with a new flush of beautiful blooms.
False sunflower pruning for the final time this season can occur in fall, after the plant has finished blooming, cutting back false sunflowers to around 2 to 3 inches (5-7.5 cm.). Alternatively, you can wait until spring to prune back Heliopsis plants so finches and other small songbirds can enjoy the seeds throughout the winter. Many gardeners appreciate the texture and interest that the spent plant provides to the winter landscape.
Additionally, postponing Heliopsis trimming by leaving the plant in place until spring also protects the ground from freezing and thawing and helps to prevent erosion. However, false sunflower pruning in fall or spring is fine. It all depends on your preferences.