Perennials are plants that live for three or more years and often require two or more years from seed to flower. There is a renewed interest in herbaceous perennials because they often need less maintenance, less water and fewer pesticides than annuals.
 
Many gardeners include flowering bulbs and ornamental grasses in this category. Once prominent in many landscapes, these enduring plants are being rediscovered for their dependable seasonal effects. Unlike trees and woody shrubs, which are also perennials, herbaceous perennials do not produce woody stems that live from year to year. The simple term "perennial" is commonly used when referring to hardy herbaceous perennials.

Perennials are easily used as ground covers, mixed with annuals, grown in containers,and used as accents or specimen plants. Many perennials are short bloomers and are best mixed with others that bloom at different times or included with other landscape plants as part of an overall design.

Consider the site before selecting your plants. Although many perennials, such as ferns, tolerate heavy shade, most perennial plants require abundant sunshine. Air circulation is important for avoiding diseases; stagnant, warm and humid air creates ideal conditions for diseases. Perennial plants also require properly prepared soil, and a few have specific drainage and fertility requirements.

Though most perennials may take a couple of years to flower from seed, many are as easily started as annuals. The quickest way to have blooming plants, however, is by vegetative propagation, such as by dividing old plants or rooting stem cuttings. Plants produced vegetatively have all of the traits of the original plant. Propagation by division may seem difficult at first, but most gardeners find that dividing crowns and roots and separating bulbs takes little experience and can be mastered quickly. Try dividing monkey grass for experience; then move on to daylilies, and before long you will have the hang of it.

Perennial plants with shallow roots are easily pulled apart by hand. Long fibrous roots can be pulled apart with a hand fork. Thickly intertwined roots may need more forceful separation or cutting with digging forks. Replant only those segments with strong roots and a few intact leaves or crowns.

In general, it is best to divide perennials during their dormant or "off" season; divide spring bloomers in the fall and fall bloomers in spring. Some perennials may need dividing every three or four years or they will slowly crowd themselves into clumps of nonflowering leaves and roots.

Many perennial plants may be propagated from stem cuttings, which does not disturb the plant's roots. Take stem cuttings during the spring or early summer, choosing stems that are mature and firm but not yet hardened and woody. Cut off 4- to 6-inch segments using a sharp knife or shears, and pinch off the succulent tip and any flower buds to force the cuttings to concentrate their energy on producing roots. Remove the lower leaves that will be below the surface of the rooting medium, but leave a few leaves to provide a source of energy for root initiation and growth.

Perennial Flowers for Louisiana

Lantana
Perennial Verbena
Butterfly Bush (Buddleia)
Perennial Salvias
Rudbeckia
Purple Coneflower
Shasta Daisy
Daylilies
Louisiana Iris

BMP Checklist:

• Select perennial flowers for your particular site and growing conditions.
• Select varieties that have proven superior in LSU AgCenter trials.
• Prepare landscape beds properly.
• Plant at the proper time.
• Dead-head to encourage re-bloom.