I’m starting snapdragons and bachelor’s buttons for the first time. The bachelor’s buttons are growing a main stalk and then budding. They’re 6-12″ high. I want more flowers. Can I pinch them back?
Can I pinch snapdragons? Those are only a couple inches high.
I checked The Gardener’s A-Z Guide to Growing Flowers from Seed to Bloom (Storey Publishing, 2004) by Eileen Powell for the answer to your question. Powell suggests that for snapdragon (Antirrhinum species) you “pinch back young plants after four to six leaves have appeared to encourage a bushy habit. Feed lightly twice before first flowers appear […] Deadhead often. If blooms become scarce, cut back plants generously, then feed and water generously.”
For bachelor’s buttons (Centaurea cyanus), the author only suggests deadheading frequently to prolong bloom. A Colorado State University Extension article from 2001 entitled “The Year of Centaurea” describes pinching back:
“Many bachelor’s-buttons branch naturally, but you can pinch the growing tips to encourage more branching, bushier growth, and more flowers. C. americana does need to be pinched, or you may end up with single-stalked plants. Pinching perennial cornflower will also give you more flowers, but it isn’t required. For slightly larger flowers, you can remove the buds from young plants, but part of the charm of cornflowers is their small, thistle like blooms.”