Rudbeckia

Family: Asteraceae
Common Name: Coneflower, Black-eyed Susan

Native to North America, these 15 species of annuals and perennials are easy to grow in almost any conditions. They are bright, flowering plants adding colour in summer and autumn, and good cut flowers. Only a few are widely cultivated.

Species

R. hirta, black-eyed Susan, zone 4, is a short-lived perennial, but usually grown as an annual from a spring sowing. It reaches about 1 m (3 ft) tall. The daisy-type flowers are yellow to orange and the raised cone of disc flowers in the centre is coloured very dark brown. Cultivated varieties are available.

R. laciniata, zone 3, is a perennial, to 1.5-2.5 m (5-8 ft). Bright yellow, daisy flowers appear in late summer and autumn. 'Hortensia' (Synonym: 'Golden Glow'), with its double flowers, is the most commonly grown form.

Cultivation

Soil must be well drained but need not be rich, although better results will be obtained from better quality soils. Grow in full sun, preferably with protection from strong wind. All can be grown from seed and perennials can also be propagated from division of existing clumps.

Climate

There are species suited to various climatic zones.