Rudbeckias (Coneflowers) for Hot and Sunny SitesDonna L. Long

Thin-leaved Coneflower (Rudbeckia triloba) Photo by Donna L. Long

Rudbeckia fulgida ‘Goldstrum’ is blooming in my hot Philadelphia garden. Summer in Philadelphia can be very hot and steamy with temperature in the high 90s and the air is wet enough to wring out water, but Rudbeckia fulgida ‘Goldstrum’ takes it all in stride. If you are looking for a native plant for your garden, then here is a bit of information on the gorgeous and tough Rudbeckias.

Rudbeckias: Composite Family Members

Rudbeckias are composite, daisy-type flowers with yellow petals and brown centers. Rudbeckias are classified as members of the Asteraceae or Composite family.

Rudbeckia flowers have a prominent raised central disc of tiny little flowers. The central disc comes in colors of black, brown, and shades of green, and mixed tones. It’s this raised central disc which gives the flowers the common names of coneflowers or black-eyed susans.

All the flowers have ray-type flowers which surround the raised central cone. The petals surrounding the raised central cone come in yellow, purple or white.

The widely known Black-eyed Susan (the annual) grows quickly from seed and often flowers the first year. Other perennials may not bloom until the second year.

We can plant Rudbeckia in the autumn to bloom next summer. Look for it at fall native plant sales.

Rudbeckia and Coneflower, informal cottage garden style

Rudbeckias are North American Natives

The genus Rudbeckia can only be found in North America. Many species can be found from Quebec to Florida and from New England to California. There are many species of Black-eyed Susans indigenous to eastern North America. The Western Coneflower (Rudbeckia occidentalis) is native to Washington and Idaho to Oregon. Good varieties for the garden include: Rudbeckia fulgida, Rudbeckia hirta, and Cutleaf Coneflower (Rudbeckia laciniata).

Rudbeckia fulgida (Orange Coneflower)

Rudbeckia hirta (Gloriosa Daisy)

Rudbeckia laciniata (Green-headed Coneflower)

Rudbeckia maxima (no common name)

Rudbeckia nitida (Herbstonne)

Rudbeckia occidentalis (Western Coneflower)

Rudbeckia serotina (Black-eyed Susan)

Rudbeckia speciosa (Showy Coneflower)

Rudbeckia subtomentosa (Sweet black-eyed Susan)

Rudbeckia triloba (Thin-leaved Coneflower)

Growing Rudbeckias in Your Garden

Rudbeckias are some of the top-selling perennials in the United States. Finding cultivated varieties bred for various colors and heights is easy. You can choose varieties which planted together will give continuous blooms from mid-summer to fall.

Rudbeckias are easy to grow from seed. If you grow them from seeds you can grow several plants for the price of one-half of one transplant. I’ve found several types of Rudbeckia at Botanical Interests. Botanical Interests sells seeds of Black-eyed Susans, Cherokee Sunset (orange flowers), Indian Summer Black-eyed Susans and other varieties.

Rudbeckia seeds on Amazon.com and on Botanical Interests.com website.

Rudbeckia fulgida 'Goldstrum' in my garden. — Rudbeckia fulgida ‘Goldstrum’ in my garden. Photo by Donna L. Long.

Growing Rudbeckia fulgida ‘Goldstrum’

Rudbeckia fulgida ‘Goldstrum’, a neat, compact with a clumping growth habit that stays need and trim in the garden. My Rudbeckia spreads and grows larger each year. So, if you plant this plant count on diving it at year or two. But, even with its expanding growth it doesn’t run and take over the garden. The straight species Rudbeckia fulgida grown up to 47 inches tall. The variety ‘Goldstrum” is shorter and more compact.

Common name: Eastern Coneflower or Black-eyed Susan

Scientific name: Rudbeckia fulgida ‘Goldstrum’

Family name: Asteraceae

Description: Short, compact plant with golden yellow petals surrounding a dark brown centers. The leaves are large and coarse textured.

Height: 12 inches

Light needed: Full Sun

Soil/Moisture needed: moist

Hardiness Zones: 3 to 9

Bloom period: July to September in Philadelphia

Bloom color: Golden yellow

Easy to Grow from Seed: Yes

Pruning and Maintenance: Long bloom period even without deadheading. Pinching the ends of stems back will produce more but smaller, blooms. Divide the clumps when they grow too large.

Disease/Problems: powdery mildew does not affect this Black-eyed Susan.

Ecosystem Roles and the Habitat Garden

Attracts: Good nectar source for butterflies and other insects

Host plant: unknown if Rudbeckia fulgida is a host plant but the Cutleaf Coneflower (Rudbeckia laciniata) is a host plant for the Streamside Checkerspot (Chlosyne nycteis)

Conclusion

Rudbeckias are not only beautiful they’re hardy and well-behaved. These bold flowers are eye-catching in the summer heat. They provide nectar for pollinators and butterflies.

Grow this native perennial and and enjoy its blooms when other plants struggle through the heat.