Perennial flowers provide color to a home garden for a set period of time each year. Gardeners choose perennials based on interesting foliage and bloom color. These plants experience a two- to three-week bloom period that requires monitoring of the flower display by the gardener. Learning how to prune perennial flowers involves distinguishing between the flowering stages of a plant and choosing the correct type of pruning method.
Learn the blooming period of each perennial flower in your landscape. Consult the plant label that came with the plant from the nursery, or research the cultivar on the Internet. This knowledge allows the scheduling of pruning to benefit the plant and limits removal of buds at inappropriate times.
Encourage healthy foliage growth to support future blooms. Remove winter mulch cover to expose new growth in mid-spring. Prune back dead foliage to the ground at this time. Don't clip new growth. Clear out the interior of the perennial to allow air circulation during leaf production.
Address foliage health in early summer after the plant has time to flesh out branches. Prune spindly branches and stems back to the center plant stem or an adjoining larger branch. Perform this thinning type of pruning to address plant size and the need for light within the plant's interior: Thinning produces stronger stems for plants that flower in the middle to late summer.
Pinch back overall foliage using pruning shears or your fingers to create a bushier plant. Perform a quick pinching by pressing a plant stem between your pointer nail and thumb right in front of the first set of leaves. Pruning forces the plant to produce additional growth at the point of each pruning cut. Limit the use of pinching right before a plant produces flowers to avoid removal of too many potential buds.
Remove spent flower blooms using a technique called deadheading. This simple pruning method requires placing a cut directly behind the head of a dying flower. Deadheading cleans up the plant and discourages seed production. The plant also directs energy toward new growth and flower bud creation.
Cut back dead foliage and flower heads as the growing season progresses. Pruning foliage that develops a burnt appearance from drought or sun exposure encourages the plant to produce further foliage as a garden accent well past the blooming period. Limit pruning after flowering to the removal of 8 to 12 inches of growth to gauge plant response.