Genial, long-blooming coneflowers (Rudbeckia spp.) are durable perennials that tolerate clay soils, hot weather, and a bit of drought. Better yet, they require little maintenance and provide attractive cut flowers.
From summer into fall, you'll find coneflowers blooming with daisy-like rays of lemon, gold, yellow-orange, yellow with mahogany streaks. A few cultivars produce dark red or reddish brown blooms. The typical coneflower has a blackish brown, chocolate, or reddish brown center, but a couple of cultivars such as ‘Irish Eyes' have lime-green or yellow-green centers. In summer butterflies visit the blooms, and in winter birds eat seeds from center "cones" left on stalks in the garden.
Common name: Coneflower
Botanical name: Rudbeckia spp.
Plant type: Annual, biennial, or perennial, depending on species
Height: 10 to 72 inches, depending on species and cultivar
Zones: Perennials hardy Zones 3 to 9, depending on species
Family: Asteraceae (Composite)
Growing conditions
Sun: Full sun to part shade
Soil: Moderately fertile, heavy, well-drained soil
Moisture: Consistently moist
Care
Mulch: Use a thin layer of compost or shredded leavest to deter weeds.
Pruning: Deadhead flowers to increase blooming.
Fertilizer: None required.
Species and cultivars
• Rudbeckia ‘Hot Chocolate' (pictured) is an annual with bicolor mahogany and yellow petals. Flowers are 3 inches across. Grows 18 inches tall.
• R. fulgida (black-eyed Susan) is a perennial with orange-yellow flowers up to 3 inches across in late summer to mid-fall. Zones 4 to 9.
• R. fulgida var. sullivantii ‘Goldsturm' has yellow flowers in late summer to mid-fall. This 1999 Perennial Plant of the Year grows 18 to 24 inches tall. Zones 4 to 9.
• R. ‘Herbstsonne' is a Royal Horticultural Society award-winner with lemon-yellow blooms on sturdy stems. It grows 6 feet tall and is hardy in Zones 3 to 9.
• R. hirta (gloriosa daisy or black-eyed Susan) is biennial or short-lived perennial often planted as an annual. Good cultivars include ‘Becky Mixed' (10 inches tall) and ‘Irish Eyes' (24 to 30 inches tall). Zones 3 to 7.
• R. hirta ‘Indian Summer' is a 1995 All-America Selections winner with huge golden blooms 6 to 9 inches across. Grows 36 to 42 inches tall. Zones 3 to 9.
• R. laciniata ‘Goldquelle' has yellow, double flowers. Grows 36 inches tall. Zones 3 to 9.
Garden notes
• Plant in large drifts for bold color in the perennial or wildflower garden.
• Combine with goldenrod (Solidago spp.), Russian sage (Perovskia atriplicifolia), and crimson Bruno sneezeweed (Helenium ‘Bruno') for a late-summer mix of texture, height, and color extravaganza.
• For winter interest, leave flower heads on stems until spring.
Pests and disease
• Slugs, snails, and aphids.
• Rust, powdery mildew, smut, and leaf spots occasionally occur.
Propagation
• Divide perennials in spring or fall.
• Sow seeds of annuals and biennials in spring.
All in the family
• The Asteraceae family includes a large group of familiar perennials such as wormwood (Artemisia spp.), goldenrod (Solidago spp.), perennial bachelor's buttons (Centaurea cyanus), globe thistle (Echinops spp.), gayfeather (Liatris spp.), sneezeweed (Helenium autumnale), and marigold (Tagetes spp.).
(Text by Mary Pestel, photo courtesy of W. Atlee Burpee Co.)