1. Plant perennials as soon as possible after the ground defrosts. Choose a location where water drains quickly after a rainfall. Prepare your planting bed by loosening and turning under the soil to a depth of 8 in. Level the soil with a rake to remove large clumps of grass and large stones.
3. Dig the hole for each plant a little larger than the root ball. Set each plant with crown even with or slightly below the level of the surrounding soil. Fill in around roots with fine soil and firm lightly, leaving a slight depression or “saucer” around the plant to catch and hold water.
4. Water your perennials. Gently add about a quart of water to the “saucer” around each plant. Water again; let soak in. Fill in loose, fine soil around clump. Water again as needed. As a weed preventative you may want to mulch your garden and then put a light sprinkling of preemergent (preen) over the mulch.
5. Mulch in cold climates. After soil freezes solid in late fall, apply a mulch around perennial clumps. Use loose straw or evergreen branches that will not pack down tightly. Remove winter mulch in spring before growth begins.
BASIC SEASONAL CARE FOR PERENNIALS
1. Spring mulching. After perennial clumps begin growth in spring, add mulch to soil around plants. Do not cover crowns. Use grass clippings, shredded leaves, compost, wood chips, etc. Mulch keeps soil moist, roots cool; prevents weed growth and adds a layer of humus which will aid future growth.
2. Stake taller perennials to prevent damage by wind. Tie plants up as they grow.
3. Pruning. When perennials have finished blooming, remove dead flower heads and stalks, to prevent the plants from setting seed and to preserve their strength. Apply a slow-release fertilizer to keep foliage growing. This will assure healthy growth and good bloom the following year.
4. Fall trimming. Some perennial plants die back to the roots in fall; cut stems back to 3-4 in. above crowns. The clump will send up new growth in early spring.
5. Dividing and Multiplying. Most perennials may be divided after 2 or 3 years to provide a continual source of new plants. To keep plants healthy, they should be divided before they become over-crowded. After 3 or 4 years of growth, dig up the root masses in early fall or spring in our area. Cut the crown of each perennial into several sections with a sharp knife, with each piece retaining its own root system. If the center portion of the old plant shows heavy, woody growth, discard it and replant only the younger outer portions of the clump. Mulch perennials heavily to provide winter protection.