By Faith Peppers
University of Georgia
"It's a misconception that because perennials last from year to year they require little maintenance and care," said Paul Thomas, a University of Georgia horticulture professor in the College of Agricultural and Environmental Sciences.
"While some perennials survive with little care," Thomas said, "more require some attention to look their best. In many cases, perennial beds require more work than annual beds."
Annual beds can be easily overhauled each year or even each season. Perennial plots are with you for the long haul. "But the rewards of perennials make the added maintenance worthwhile," Thomas said.
Thomas offers these tips to keep perennial beds looking their best:
Watering. Perennials' drought tolerance varies, but more require an ample moisture supply at least during active growth. Don't rely on normal rainfall. Water if necessary.
Allow the water to penetrate deeply. Frequent, light waterings aren't advisable because they wet only the upper soil and result in shallow root growth and wet foliage and flowers. That's an invitation to many diseases. Soaker hoses and drip irrigation systems work well with perennials.
Mulching. To help conserve moisture, control weeds and improve the overall appearance of the garden, you need to mulch perennials. Mulches also tend to prevent soil crusting, which retards water penetration, and prevent soil from splashing on lower leaves and flowers.
Mulches provide an added degree of winter protection, too. A word of caution: Heavy mulches that hold moisture can be detrimental, particularly to plants subject to crown rot. Pine bark, pine straw, wood chips and a variety of other materials are good.
Fertilizing. Maintenance fertilization is essential to the continued growth of perennials. Apply 8-8-8 or 10-10-10 (1.5 pounds per 100 square feet) in early spring and once or twice again during the growing season.
Base maintenance fertilization on soil tests. Applying phosphorus is often not needed once adequate soil levels become established. Water the bed after applying so the fertilizer enters the soil and is available to the plant. Wash any fertilizer off the foliage to prevent fertilizer burn.
Controlling weeds. A well-prepared bed requires little cultivation. Deep cultivation is likely to injure roots and often uncovers weed seeds, which can then germinate. Weed control should usually be done by hand weeding or with herbicides.
Use extreme caution when using a herbicide. Very few are suitable for use around perennials. Read the label carefully to be sure it won't injure desirable plants.
Defoliating. Remove dead foliage and stems in the fall. It's natural for the tops of many perennials to be killed to the ground by frost. Some herbaceous perennials have evergreen foliage.
Dividing and propagating. While the length of time varies, most perennials eventually become overcrowded and require division. Mature clumps can be cut or pulled apart. Divisions should usually contain three to five shoots or growing points. Discard any weak or diseased divisions.
The time to divide perennials varies somewhat, but it's most often fall or early spring, coinciding with desired planting dates. Many perennials are easily propagated in this way.
To find out more about growing and caring for perennials and a good list of perennials that grow well in Georgia, see the Georgia Extension Service publication, "Flowering Perennials for Georgia Gardens" (http://pubs.caes.uga.edu/caespubs/pubcd/b944-w.html).
(Faith Peppers is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)
(Faith Peppers is the director of public affairs with the University of Georgia College of Agricultural and Environmental Sciences.)