(Geranium x magnificum), or hardy geraniums, are versatile, easy-care, long-lived perennials that thrive in full sun to part shade. Often confused with their tender cousins, Pelargonium, they bloom in shades of white, pink, blue, and purple from late spring to early summer, reblooming in fall if cut back.
Daylilies (Hemerocallis) are favored for their abundant, trumpet-shaped blooms and resistance to most pests and diseases. They prefer full sun but tolerate part shade in most areas, and by selecting carefully, it's possible to have color all summer. 'Siloam Ethel Smith,' which has unusual beige-pink flowers with a lime throat, is one of more than 30,000 named cultivars.
Phlox, a favorite for cutting, prefer full sun but tolerate part shade, and bloom in shades of white, pink, red, purple, and blue from summer into fall. In humid regions, choose mildew-resistant cultivars. 'Franz Schubert' garden phlox (Phlox paniculata) has dense heads of lilac-pink flowers with pale-blue margins.
PERENNIALS FOR SHADE
Bleeding heart (Dicentra spectabilis), features ferny, finely cut leaves and lovely pendant, pink and white heart-shaped flowers on graceful stalks in spring. Excellent in a woodland garden, it requires part to full shade; in hot regions it dies back by midsummer.
Hostas, often grown as ground covers, are easy-to-grow shade lovers that bear graceful, often fragrant, white or lavender blooms above mounds of lush, broad foliage in many shades of green, blue-green, and chartreuse. 'Royal Standard' has glossy, pale-green leaves and white funnel-shaped flowers in midsummer.
New gardeners often find perennials daunting, but experienced ones know that carefully chosen perennials mature into a garden with multiseason interest. Strictly defined, a perennial is any plant that persists for more than two years (some live for decades, others only a few years), and because of this, creating a perennial border requires a longer commitment than planting a bed of annuals. But this longevity allows you to refine your plantings over time, adding and rearranging until you have achieved your desired effect.
The best time to plant perennials is in spring or fall, when the weather is cool and moist. But container-grown perennials can be planted anytime during the growing season if you keep them well watered until they are established.
Most perennials need a sunny location to thrive, but many tolerate or thrive in part sun to full shade. In general, plants that require "full sun" need at least six hours of direct sun daily. "Part sun" or "part shade" plants flourish where periods of direct sun alternate with periods of shade, or where sunlight is filtered or dappled, for example, beneath overhead branches. "Full shade" describes a spot where direct sun never penetrates.
Keeping a perennial border trim requires regular attention: weeding, watering, deadheading, and feeding. In addition, plants that outgrow their space must be divided (which rewards the gardener with more plants) and failing plants must be moved or replaced.