Perennial plants and flowers are the backbone structure of the garden because they regrow and multiply each year. Perennials grow and bloom for more than two seasons, some of them for many years. Perennial flower plants thrive with good pruning and good care. There are a few pruning methods to know about before you plant perennials. Pruning, pinching back and thinning are ways to encourage perennial plants to bloom well. They are each a way to force the plant to use its energy to grow more flowers on stronger stems.
Some perennials such as salvia and lady's mantle benefit from pruning after they flower in the summer. The plants then go dormant until next spring. Shasta daisy and yarrow re-energize by having a dormant phase after blooming.They should be cut back after blooming to the leaves at the base of the plant. Some early bloomers such as candytuft, phlox and rockcress can be pruned after they flower in early summer and they will bloom again in late summer. Cut the stalks back to half their height.
Dead-heading and Dis-budding
Remove faded flowers as the blooming period gets under way. Remove the faded blossoms and stem down to the next set of leaves. This is called deadheading, and it prevents the plant from wasting energy on unwanted seed production. Perennials grown for large showy blossoms, such as chrysanthemums and peonies, should be dis-budded as flowers develop. This encourages fewer but larger blossoms. Pinch off smaller lateral buds, leaving one in the middle to develop.
Perennials such as garden phlox and beebalm are subject to mildew. Cut half the stems to ground level when they are about one-fourth of their expected height. This ensures good air circulation and growing room for the rest of the plants. Good air circulation prevents mildew from developing.
Perennials grow well in loose, rich organic loam soil that is renewed yearly. Clear the perennial bed of weeds and old plant growth before you prepare the soil. They need soil rich in nutrients and living organisms. Add compost from your own compost bin or purchased compost from a garden center. "Side dressing" means to add organic compost on top of the soil near the plant base several times during the growing season.
Perennial plants need to be divided every three to four years. There are three signs that a perennial plant needs to be divided: flowers have become smaller, it has overgrown its allotted space or it has a bare spot in the middle of the clump. The best time to divide plants is at the beginning of the growth season in spring. Dig up the plant, lay it on a tarp and carefully pull apart the root system.