Many plants benefit from occasional barbering, whether the purpose is to promote more bloom or simply to produce a more pleasing shape. The method to use depends on the plant.
Deadhead (trim or pinch off regularly) the spent flowers of all annuals and the many perennials that bloom over a period of time instead of all at once (see "eHow to Deadhead Flowers'). There are dozens of long-blooming perennials, including balloon flower, yarrow, sage and peony.
Step2
Pinch back annual flowers, vegetables, herbs and late-blooming perennials such as chrysanthemums and asters. You'll help the plants produce more flowers and make them fuller and denser.
Step3
Shape perennials that bloom in a single flush, such as lavender and false indigo, to produce a form that blends well with other plants in your garden. Use sharp shears to cut foliage back by about a third, creating a shape that blends in with later-maturing plants in your garden.
Step4
Cut plants prone to legginess all the way back to the ground after they bloom. Hardy geraniums, Japanese anemone and black-eyed Susan all lend themselves well to this treatment.