For most gardeners, perennials form the backbone of the flower bed. Although new annual flowers must be planted every spring, perennials return to stage a repeat performance year after year. Perennial plants vary in size, color and form, and their care requirements vary as well. However, most perennials are relatively low-maintenance plants that will perform dependably with minimal care. Tending the perennial garden involves providing adequate water, fertilizer and protection from winter cold.
Water perennials regularly. Although some perennials can survive with little water, most will benefit from plenty of moisture, especially during hot, dry weather. Water deeply so the water soaks the roots, then allow the soil to dry slightly before watering again. Water at the base of the plant and avoid wetting the foliage. Water during the early part of the day so the plant can dry before evening.
Feed perennials a balanced, time-release fertilizer in early spring, early summer and late summer. Apply the fertilizer in a circle around the base of the plant, then water deeply. Don't allow fertilizer to come in contact with the foliage. Check the fertilizer container for specific rates of application.
Pinch off (deadhead) spent flowers. Pinch the bloom and the stem down to the next stem or leaf. Deadheading will cause the plant to keep blooming as long as possible, and will prevent the plant from going to seed too early.
Stake tall perennials in spring while the plants are still small. Install a wooden or metal stake next to the plant. Tie the stem loosely to the stake with garden twine or soft fabric.
Mulch perennials in spring or early summer to cool the roots, deter weed growth and retain soil moisture. Apply 2 to 3 inches of an organic mulch such as chopped leaves or pine mulch around the perimeter of the plant, but don't cover the plant.
Cut perennials down to within 4 to 6 inches in early autumn. Apply 3 to 6 inches of fresh organic mulch before the first frost. Mulch will insulate the soil and protect the plant from freezing and thawing.
Divide perennials when the center of the plant begins to become woody and unproductive. Divide perennials when the plant is dormant in autumn or early spring. Dig the entire clump with a spade or garden fork. Pull the plant apart into smaller sections. Each section should be large enough to have several roots. Discard the woody portion and replant the divided sections.