Get a second summer blooming from many perennial flowers in your garden by cutting them back. Cutting back is an aggressive trimming that removes spent flowers, stems, leaves and seeds so that the plant will concentrate its energy on producing new healthy leaves and flowers for a second time in the season. Not all perennials will bloom again after cutting back. Hollyhock, bachelor's buttons, delphinium and clematis are a few varieties that will give a second show after a trim.
Plan to cut back after the plant is done or nearly done with its first flowering of the season. It should be starting to look bedraggled with many spent blooms.
Use a kneeling pad or wear knee pads. Get down on the ground to see the plant from the bottom up clearly.
Snip off each flower stem down to 1 inch above the ground with a pair of sharp garden shears. Perennials with a strong root system will not be damaged by aggressive pruning.
Apply a nitrogen-rich flower fertilizer to the soil surrounding each plant following package instructions for proper application.
Keep soil moist at all times as the plants grow their new foliage. Second blooms will begin to set within 4 to 10 weeks.