There are three regional varieties of Rudbeckia hirta, the wild black-eyed Susan, with one occurring naturally throughout much of North America from British Columbia to Newfoundland and south to Texas and Florida. The species is absent only from the Southwest. Black-eyes Susans grow in prairies, dry fields, open woods, along road shoulders and in disturbed areas.
Rudbeckia hirta is a biennial/Perennial plant, that can reach a height of 1 m. It has alternate, mostly basal leaves 10-18 cm long, covered by coarse hair. It flowers from June to August, with inflorescences measuring 5-8 cm in diameter (up to 15 cm in some cultivars), with yellow ray florets circling a brown, domed center of disc florets.
It is hardy to zone 4. It is in flower from July to October, and the seeds ripen from August to October. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees, hoverflies.
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils. The plant prefers acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It requires moist soil. The plant can tolerates strong winds but not maritime exposure.
Succeeds in an ordinary medium soil in sun or shade. Requires a moist soil. Prefers a well-drained soil. Dormant plants are hardy to about -25°c. This species is a biennial or short-lived perennial. Some named forms have been selected for their ornamental value. Members of this genus are rarely if ever troubled by browsing deer.
Seed – sow April in a greenhouse. Only just cover the seed. Germination should take place within 2 weeks, prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer. The seed can also be sown in situ
The roots but not seedheads of Rudbeckia hirta can be used much like the related Echinacea purpurea. It is an astringent used as in a warm infusion as a wash for sores and swellings. The Ojibwa used it as a poultice for snake bites and to make an infusion for treating colds and worms in children. The plant is diuretic and was used by the Menominee and Potawatomi. Juice from the roots had been used as drops for earaches.
The plant contains anthocyanins.
*A yellow dye is obtained from the flowers.
*The Black-eyed Susan was designated the state flower of Maryland in 1918.
*Butterflies are attracted to Rudbeckia hirta when planted in large color-masses.
*Numerous cultivars have been selected for garden planting; some popular ones include ‘Double Gold’, ‘Indian Summer’, and ‘Marmalade’.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.
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