FIRST IMPRESSIONS: Rudbeckia triloba is a bushy biennial or short lived perennial wildflower. Leaves are toothed and pubescent with three lobes. From mid-summer until autumn plants are crowned with a profusion of dainty daisies. Individual flowers are 1-2” across with dark brown centers and bright yellow rays. Plants thrive in sunny sites with moist or dry soil.
HABITAT & HARDINESS: Rudbeckia triloba occurs from Vermont to Florida and west to Minnesota, Nebraska, Colorado, Utah and Texas.
This species is indigenous to Blackland prairies, savannas, thickets, woodland edges and clearings, edges of fens, creek and river banks, disturbed prairie remnants, abandoned fields, roadsides and railroad right-of-ways. Plants occur in high quality natural areas but are found more often in disturbed sites.
Plants are hardy from USDA Zones 4-8.
PLANT DESCRIPTION: Rudbeckia triloba is a clump forming perennial with many upright branching stems. The stems can be pubescent with reddish color.
Leaves are 4” long and 2” wide with coarse teeth and rough surface. Most are three-lobed.
Foliage is crowned by an array of flower-heads from summer until fall. Each is 1-2” across with 6-12 golden-orange rays. The rays encircle a brown or black cone containing many disc florets.
The cone matures into a persistent brown flattened seed head.
Plants grow 2-5’ tall with 2-3’ spread.
CULTURAL & MAINTENANCE NEEDS: Rudbeckia triloba is an easily cultivated sun loving plant for moist well drained soils. Plants tolerate drought, gravelly, clay or sandy soil and part sun.
Deadheading prolongs the blooming season and helps maintain a tidy garden. If seedheads are not removed, the seed feed the birds.
This is a short lived species but it readily reseeds and supplies a new crop of seedlings.
LANDSCAPE USES: Rudbeckia triloba is a great choice for a Wildlife Garden or a Meadow. Also useful as an Accent, Butterfly Nectar Plant or as part of a Grouping or Mass Planting. This species provides Showy Blooms and Cut Flowers and can be used in Cottage Gardens, Water-wise Landscapes, Low Maintenance Plantings, Perennial Borders, Roadsides, Restoration Projects and Rock Gardens.
COMPANION & UNDERSTUDY PLANTS: Rudbeckia triloba mingles well with Andropogon gerardii, Asclepias tuberosa, Baptisia tinctoria, Coreopsis tripteris, Echinacea purpurea, Liatris aspera, Monarda punctata and Panicum virgatum.
Rudbeckia hirta offers similar appearance and provide the same quick effect.
TRIVIA: A variety of native bees, beneficial wasps, flies and beetles sip nectar and forage for pollen on the flowers. The foliage is occasionally browsed by deer, rabbits and groundhogs.
Rudbeckia triloba won the 1997 Georgia Gold Medal. The Gold Medal Plant Program promotes the use of superior ornamental plants in Georgia.
Rudbeckia triloba has smaller flower heads, fewer rays and later blooming time than most other Rudbeckia spp. Plants bloom in late summer and autumn a few weeks after Rudbeckia fulgida ‘Goldsturm’ and Rudbeckia hirta. This species is taller and bushier than Rudbeckia hirta. It is shorter and has fewer lobes than Rudbeckia laciniata.
In the eastern part of its range, Rudbeckia triloba tends to occur in sunny dryer habitats like tallgrass prairies. Further west, this species is found more often in wetlands or wooded sites.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=RUTR2