Dictionary of Flowers: Rudbeckia
(Black-Eyed Susan)

Rudbeckia is also known as Black-Eyed Susan. Image used under a Creative Commons licence with the kind permission of smilla4 and Flickr

Rudbeckia is also known as Black-Eyed Susan. Image used under a Creative Commons licence with the kind permission of smilla4 and Flickr

  • Rudbeckia
  • Common name: black eyed susan
  • Family: Asteraceae
  • Category: perennial in USDA zones 3 to 7. Biennial  and annual species also exist
  • Height: 24" to 36"
  • Width: 12" to 24"
  • Sun
  • Blooms: summer to early fall
  • Attracts: birds, butterflies
  • Growth habit: upright, clumping. Used as a filler or thriller in container combinations
  • Maintenance: easy
  • Soil: average to rich, well drained. Water regularly if grown in containers. Drought resisant
  • Garden uses: containers, mixed border, wildflower garden, cutting garden
  • Diseases: powdery mildew
  • Pests: slugs and snails on young plants

A prairie flower native of the United States, Mexico and Canada, black eyed susan is either a herbaceous perennial, biennial or annual garden plant.

Cultivated varieties bear large yellow daisy-like flowers with dark centers that grow on tall stems. The plant's leaves are medium to dark green, hairy and grow forming a basal clump from which the flowers rise.

Flowers range in color from yellow to gold and mixed bronze or mahogany and yellow. There are single, semi-double and double forms. Pollinators and birds love the flowers.

The seedheads are dark, conical and can be left in place during winter for both garden interest and to provide wild birds with food. It is useful in the garden to provide mid to late summer interest, when other perennials start to decline.

Easy to grow, black-eyed susan is not particular about soil pH or soil quality. It grows in sandy or clay soils, average to slightly fertile, but well drained.

It accepts average amounts of water and once established, it is fairly drought tolerant. It prefers full sun, but will tolerate some shade, though plants grown in part shade might require stalking as they tend to lean and produce less or smaller flowers.

Deadhead to the main stem to keep rudbeckia blooming and leave seedheads in place at the end of the season to collect seed or for winter interest.

Black eyed susan doesn't mind the summer heat. It spreads by rhizomes and by seed, and it can self seed some.

Fertilize sparingly, once in spring with a slow release granular fertilizer. They can be divided in early spring to improve air circulation if clumps get too crowded. 

IWILLWRITECAPTION. Image used under a Creative Commons licence with the kind permission of NAMEOFFLICKRUSER and Flickr

Black eyed susans are easily available in nurseries as starting plants. They are easy to propagate by either division of the clump or by seed,  indoors or outdoors.

To start outdoors, scatter seed in place in either spring or fall. Keep seedbed moist. When seedlings germinate, thin out the weakest to about eight inches apart.

Black eyed susan seed can also be wintersown. To start indoors, ten to twelve weeks before last frost date, plant seed in moistened starting mix and do not cover.

When kept at around 70F, seed should germinate in one to two weeks. If germination doesn't take place, move starting containers to the refrigerator and keep there four weeks.

Bring back to room temperature. Once seedlings appear, move to a sunny position or grow under lights. Harden off for about a week, and plant in their permanent location right around the last frost date. If started in late winter, they might bloom the first season.




IWILLWRITECAPTION. Image used under a Creative Commons licence with the kind permission of NAMEOFFLICKRUSER and Flickr

Rudbeckia is deer resistant. It isn't disease prone, except for powdery mildew when grown in crowded conditions or during hot, humid summers.

Improve cultivation conditions and treat with fungicide. It isn't likely to be bothered by pests. If slugs and snails become a problem in spring, bait as needed.

Popular varieties:

  • Rudbeckia fulgida var. sullivantii 'Goldsturm' - two to three feet plants, perennial species. Large yellow flowers up to four inches diameter
  • Rudbeckia fulgida speciosa 'Viette's Little Suzie' - compact variety, up to sixteen inches tall. Large flowers, but on short stems
  • Rudbeckia fulgida 'City Garden' - twelve inches tall, yellow flowers
  • Rudbeckia hirta - biennial or short lived perennial. Yellow to orange flowers, up to three inches diameter on three feet high plants
  • Rudbeckia hirta 'Autumn Colors' - grows up to two feet, blooms have mahogany centers
  • Rudbeckia hirta 'Becky Mix' - small variety of r. hirta, up to twelve inches high. Compact size, but with large flowers
  • Rudbeckia hirta 'Cherokee Sunset' - up to three feet high. Blooms are double or semidouble, yellow and mahogany or bronze
  • Rudbeckia hirta 'Irish Eyes' - tall variety, up to four feet. Yellow flowers with bright green centers
  • Rudbeckia hirta 'Prairie Sun' - slightly shorter than Irish Eyes, similar in appearance. Light yellow flowers with green centers

IWILLWRITECAPTION. Image used under a Creative Commons licence with the kind permission of NAMEOFFLICKRUSER and Flickr

Full List of Dictionary of Flowers Entries

Annuals For Containers

Perennials For Containers

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