Perennials are plants that live for three or more years. The word perennial describes non-woody plants that reliably survive winter cold and are grown for their attractive flowers or foliage.
In the landscape, perennials often need less maintenance, as well as less water and fewer pesticides, than annual bedding plants.
Perennials are easily used as ground covers, mixed with annuals, grown in containers and as accents or specimen plants, says LSU AgCenter horticulturist Allen Owings. Because many perennials bloom for only short periods, they do best mixed with others that bloom at different times or included with other plants as part of an overall design.
Although some perennials, such as ferns, tolerate heavy shade, most require plenty of sunshine.
You may not think about planting perennials this time of the year, but the success of fall- through late-winter planting is good, Owings says.
Good choices for perennials for Louisiana include lantana, perennial verbena, butterfly bush, Mexican heather, coneflower, rudbeckia, perennial salvia, iris, daylilies, Shasta daisy and coreopsis among others. Check with garden center professionals or plant tags to select perennial flowers appropriate for your particular site and growing conditions.
You can propagate new plants by dividing old plants or by rooting stem cuttings. The resulting plants will have all of the traits of the original plant.
In general, it is best to divide perennials during their dormant or "off" season, dividing spring bloomers in fall and fall bloomers in spring. Some perennials may need to be divided every three or four years or they will slowly crowd themselves into clumps of nonflowering leaves and roots.
Perennials 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.
Take stem cuttings during spring or early summer, choosing stems that are mature and firm but not yet hardened and woody. Cut off 4- to 6-inch segments, and pinch off the succulent tip and any flower buds. 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. Then plant the cuttings in pots to get them started before introducing them into the landscape.
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