Every year my hardy chrysanthemums start blooming in early July, even though I pinch them back. This year I pinched them twice and still they are coming too soon. When and how does one pinch a chrysanthemum properly? Does the amount of direct sun make a difference?
Most northern gardeners worry their chrysanthemums won’t bloom before the snow flies in fall. Pinching mums back to 6 inches helps keep mums compact but it does delay bloom. Those gardening in areas with a long growing season keep pinching their mums until mid July or the first of August. Those gardening in shorter seasons stop pinching in late June to early July. To pinch: remove the top inch or two of new growth once or twice a month to keep plants 6 inches tall. Pinch your plants twice a month to encourage leaf growth and discourage flowering. Keep the soil slightly moist, not wet, and plants fertilized properly to avoid stress that can induce bloom.