Peony Perennials

Attractive, long-lived, bushy plants that bear numerous 3"-6" blossoms, peonies are the perennial gardener's dream come true. Early summer flowers arrive in shades of pink, red, white, and yellow amid glossy, lobed, green foliage; plants form neatly rounded clumps roughly 3'-4' tall.

Peonies prefer full sun and moist, well-drained, richly organic soil, although light shade is tolerated and may prolong bloom in the South. A protected site limits wind damage to blossoms. Most are hardy to Zone 5 and do best in cold-winter climates.

Easy to care for in most respects, peonies are finicky about planting. Set rootstocks so that the reddish buds or "eyes" are no more than 1 "-2" below the soil surface. Mulch after the ground freezes the first winter after planting to prevent heaving. Divide roots in fall, if necessary, leaving at least 3 buds on each section. Cut stems back to below ground level in fall.

Problems

Flower buds absent. Causes: Improper planting; excess shade; immature plant; large, old crown; excess nitrogen; disturbed roots. Choose planting sites carefully; set roots at the proper depth; be patient with new plants. Do not apply high-nitrogen fertilizers. If mature peonies stop blooming, rule out other possible problems and divide if needed—division and other root disturbances also reduce bud formation.

Flower buds don't open. Causes: Late spring frost; drought; high temperatures; low soil fertility. Weather extremes notwithstanding, water adequately and feed peonies with compost or a slow-acting, general-purpose fertilizer in spring. If summer heat is the problem, plant early flowering cultivars.

Flower buds die or petals distorted. Cause: Flower thrips. These '/i»" insects feed on buds, stem tips, and flowers, causing distortion or white, brown, or red flecks. Thrips are hard to control because they burrow into plant tissue. Remove and destroy infested plant parts. Encourage natural predators such as pirate bugs, lacewings, and lady beetles. Use blue sticky traps to monitor and trap pests. Insecticidal soap sprays may provide some control once pests appear on traps.

Stems with sunken lesions. Cause: Anthracnose. Sunken lesions with pink blisters appear on stems. Plants may die. Cultural controls such as regular fall cleanup and thinning stems to improve air circulation are effective. Treat severe problems with copper fungicide sprays.

Shoots wilt, collapse; crowns with gray mold. Cause: Fungal diseases. Several fungi cause blights or stem and crown rots in peonies. Botrytis blight causes shoots to wilt suddenly and fall over. Stem bases blacken and rot; gray mold may appear near soil; buds may wither and blacken. Flowers and leaves may turn brown and develop mold. Remove and destroy infected plant parts. Don't put manure near plant crowns; clear mulch from crowns in spring to let soil dry. Avoid overwatering and wet, poorly drained soil. If problems persist, scrape away the top 2" of soil around plants and replace with clean sand. In spring, spray shoots with bordeaux mix.

Plant stunted; leaves yellow, spotted; roots with tiny galls. Cause: Root knot nematodes. Feeding by these microscopic pests reduces roots' ability to take up water and nutrients. Control root knot nematodes by applying chitin or parasitic nematodes to soil. Also promote natural nematode controls by increasing soil organic matter. Drenching soil with neem may provide some control. In severe cases, remove plants, solarize the soil, and replant with nematode-free stock.

Papaver

Poppy. Perennials.

History has heaped symbolism upon the brightly colored blooms of poppies, yet these broad, crinkled flowers burst forth undeterred in spring and early summer. The diminutive alpine poppy (Papaver alpinum) offers 1" blooms and 8"-10" height, while Iceland poppy (Pnudicaule) and Oriental poppy {P orientate) can exceed 1' in height and spread, with 3"-7" flowers. Deeply divided, hairy, gray-green foliage surrounds leafless flower stems, each with a single bloom.

Most poppies are very hardy and perform best in cool summers and cold winters; grow plants as annuals in warmer climates. Full sun to light shade and well-drained soil satisfy poppies' needs: established plants tolerate some drought, but soggy soil guarantees rotting of fleshy roots. Foliage dies back after flowering ends, and plants disappear by late summer. Mark the spot to avoid digging injury to roots. New leaves appear in fall. Divide every 5 years, in late summer, to maintain vigor. Poppies self-sow if allowed to set seed; seedlings may not come true to parents.

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