How to Grow Black-Eyed Susans

Black-Eyed Susans, Rudbeckia hirta, are tall-growing perennials. They are golden yellow in color, with a dark brown coned center.
One of the most popular and recognized flowers, Black-Eyed Susans have been a gardener’s favorite for generations.

Their extended flowering season gives gardeners a vibrant burst of color when most other flowers are spent. Because of their easy care and long bloom time, Black-Eyed Susans are a must-have for any butterfly garden.

Hummingbirds and butterflies flock to these bright flowers. Finches and wrens are also attracted after the flowers go to seed. Black-Eyed Susans have proven to be an easy growing perennial that gardeners have come to depend on for years.

There are 25 species of Rudbeckia and all are native to North America.

Black-Eyed Susans look great when planted with purple coneflowers, Russian sage, among vitex and near lilacs. The giant variety is also attractive with cosmos, penstemons, tall cannas, and background accent plants. The plant does very well as a cut flower. It’s a summertime bloomer and provides flashes of color in a hot weather garden.

What do they look like?

Black-Eyed Susans have brown domed centers, surrounded by yellow ray florets. The stems and leaves are covered with small hairs. Mostly found in shades of bright yellow to deep golds.

How tall do they get?

These tall-growing perennials range in height from 18 – 72 inches. There are several varieties of Black-Eyed Susans. Each one varies on height and width. Most only reach an average height between 24 – 36 inches.

What spacing should I use?

They should be spaced approximately 18 inches apart. If you are using one of the larger varieties of Black-Eyed Susans, then increase the amount of space you leave between plants. Black-Eyed Susans are not considered to be invasive plants. They will propagate by seeding or division. Hybrid plants need to be divided to maintain the desired characteristics of the parent plant.

Black-Eyed Susans grow well from seed, which germinate in between seven and 30 days, and require little care. Water regularly the first few weeks to establish them and then irregularly afterward.

How much sun do they need?

These plants will grow best in full sun. They will tolerate partial shade. However, the number of blooms produced will significantly decrease if given less sunshine.

What type of soil do they grow best in?

Soil should be fertile and well-drained. Too much moisture may cause mold to grow on leaves. Do not over-fertilize these plants. They prefer soil to have a pH of less than 6.8. Use a slow-release fertilizer, over 3 months.

What growing zone do they require?

They will be successful in growing zones 4-9. The exact zone will be dependent on the variety of Black-Eyed Susan you have chosen.

When will they bloom?

They are amazing flowers. They will bloom continuously, from late June through late September. They are a garden favorite because of their durability and colorful blooms. They will bloom continuously from late summer to early fall. They are a welcome burst of color between growing seasons.

What special care do they require?

They are known for their hearty nature and durable growth season. Once established, they will need little upkeep. Trim deadheads off at the end of the blooming period. Keep the mulch at a minimum. Too much mulch packed around the bottom will encourage mold to form on leaves and stems. Do not overcrowd plants. Proper ventilation will lead to strong healthy plants.

Interesting Facts

• Indigenous to the United States, they are found along roadsides and gardens all across the country. Since they can be found growing both in the wild and in gardens, they are considered one of the most well-recognized flowers.
• When roots are boiled in water, the juices can be used as an astringent, for swelling, and open sores.
• Native Americans used this plant in a poultice for respiratory infections and snake bites.

Are Black-Eyed Susans the same as Coneflowers?

The plant is called a coneflower. But it shouldn’t be mistaken for other plants also known as coneflowers. While all Black-Eyed Susans are of the genus Rudbeckia, other plants are called “coneflowers”, including purple coneflowers (Echinacea), Mexican hat (Ratibida) and clasping coneflower (Dracopsis). However, all are in the Aster family (Asteraceae), and the purple coneflower is closely related to Rudbeckia.

What Other Black-Eyed Susans Are Out There?

Giant Black-Eyed Susans

Giant Black-Eyed Susans (Rudbeckia Grandiflora), also known as rough or tall coneflowers, stand tall in any garden. Large, alternating, gray-green leaves ladder up a tall stalk, which could rise to six feet. The centers of the flowers are also gray-green, but turn brown in a few days.

It ranges as far north as Ontario, south to Texas and Louisiana, and east to Georgia. However, other varieties of Black-Eyed Susans have naturalized fields, pastures, meadowlands and roadsides throughout most of North America, including British Columbia and Newfoundland to the north and Florida and south Texas to the south. The plant has not been very successful in the southwest. Giant Rudbeckia is usually found in warmer zones (7 – 9) but in general, the genus thrives in zones 3 through 9).

Although it is a perennial in many areas, the plant can also be an annual or even a biennial. As a perennial, it is short-lived. Giant Black-Eyed Susans bloom from April through August.

Goldsturm Black-Eyed Susans

According to the literature sent out in the news release about this plant, it was first discovered in 1937 in Czechoslovakia. World War II intervened and the plant was not introduced to the nursery trade until 1949. It is now grown around the world and well-deserving of the being named the perennial plant of the year.

Goldsturm is another example of Europeans taking a North America “wildflower” and developing cultivars from it. The species that Goldsturm developed from is native from New Jersey to Illinois and is a relatively pest-free plant frequently found in meadows. During the winter it serves as food for the birds and provides summer nectar for butterflies. Sometimes we Americans fail to recognize the quality of plants in our own wild fields and roadways.

The name, ‘Goldsturm’ translates from German into “gold storm”, an excellent description of this plant in full bloom. The flower heads consist of 1-2″ gold petals surrounding a center blackish-brown cone. Common names are both black-eyed Susans and orange coneflower.

It is a member of the aster (Asteraceae) family. It grows about 18″ tall with a width of 24″. Like so many outstanding plant cultivars, the only sure way to get this plant is through divisions, stem cuttings, or tissue culture. Seed grown plants may not have the same color or size.

Goldsturm requires little maintenance. I grow it in a high clay content soil (hard as a brick in drought conditions) and it still produces a nice show. The growers recommend a “well-drained, consistently moist soil.” All plants do better in ideal conditions, but this plant thrives in less than ideal too. It thrives from South Carolina (heat and humidity) to Alberta Canada with its -35°F temperatures.