Brown-Eyed Susan vs. Black-Eyed Susan: What’s the Difference?

Many gardeners and floral enthusiasts have heard of black-eyed susans, the lovely biennial flower with golden petals and a black center that grows in abundance as wildflowers around the United States. They are classic flowers that can suit any garden, landscaping project, or floral arrangement. Often, black-eyed Susans are referred to as brown-eyed Susans. However, when it comes to the brown-eyed Susan vs. black-eyed Susan, they are actually completely different species. While very similar appearance-wise, these lovely flowers have some notable differences worth knowing if you plan on planting them in your own garden.

In this guide, we’ll explore all of the differences between black-eyed Susans and brown-eyed Susans, so you can make a more informed decision about which plant will make your garden its new home.

Comparing Brown-Eyed Susan vs. Black-Eyed Susan

The Key Differences Between Brown-Eyed Susan and Black-Eyed Susan

If you put black-eyed Susans and brown-eyed Susans beside one another, it might seem impossible to tell the differences between them. After all, black-eyed susans are commonly confused for their brown-eyed counterparts. While they share a genus, these two flowers are completely different species.

To start with differences, brown-eyed susans have somewhat smaller flower heads and fewer rays than black-eyed susans. Brown-eyed Susans tend to bloom in late fall or summer, notably a couple of weeks after black-eyed Susans have already bloomed.

As one can gather from the titles of these flowers, the black-eyed Susan tends to have a darker center than the brown-eyed Susan. However, it is worth noting that both of these species have a set of varieties within their species, so the hue of the center of either black-eyed or brown-eyed susans can vary.

There’s also a difference between their native locations. Brown-eyed Susans tend to grow in the United States and Canada from the eastern region of Texas up toward Quebec. Black-eyed Susans can be found virtually anywhere in the United States and Canada.

Brown-Eyed Susan vs. Black-Eyed Susan: Classification

Brown-eyed Susans are classified as rudbeckia triloba. Black-eyed Susans are classified as rudbeckia hirta. The rudbeckia genus, also known as the coneflower genus, contains about 20 species of flowers that look quite similar to the black-eyed susan and brown-eyed susan. Both of these plants are closely related to the California coneflower, the western coneflower, and the cutleaf coneflower.

Brown-Eyed Susan vs. Black-Eyed Susan: Description

The brown-eyed Susan grows readily in typical, moist, well-drained soils and is a herbaceous biennial or short-lived perennial. It is a hardy plant that resembles weeds and can withstand heat, drought, animal predation, and a variety of soils. With two to four-inch leaves and two to three-inch yellow blooms with dark purple-brown center disks, the plant often grows to a height of five feet. The leaves, which frequently have three lobes and a rosette of leaves that start at the base of the stem, tend to last all winter long and make for a lovely ground cover.

The short-lived perennial or biennial black-eyed Susan is rigid, erect branching, and grows somewhat quickly. It typically develops as a biennial and can grow up to four feet tall. It can be seen growing along banks and by the sides of roadways. The margins of the alternating leaves are serrated or nearly smooth. Three or more lobes are possible in some leaves. Flowers have a brown, domed center surrounded by bright yellow ray florets that become fully developed in the middle of the summer.

Brown-Eyed Susan vs. Black-Eyed Susan: Uses

Both brown-eyed and black-eyed Susans are great pollinator plants. Native bees and butterflies are particularly attracted to these plants, as well as birds who consume their seeds. Both of these American flowers are used for gardening, flower arranging, and landscaping.

Black-eyed Susans are unique in that they have been used as medicine. Black-eyed Susan roots can be infused in several Native American herbal remedies to treat colds, dropsy, and worms in younger children. While the liquid found inside the black-eyed Susan’s roots has been utilized as earache drops, this mixture has also been used for wounds and snake bites.

Brown-Eyed Susan vs. Black-Eyed Susan: Origin

Brown-eyed Susans are native to New England, Minnesota, Georgia, and Oklahoma. The majority of the midwestern United States, where it has naturalized in woodlands, bare fields, and rocky slopes, is also thought to be its native territory.

Native to much of eastern and central North America, black-eyed susans can be found along roadsides, in open prairies, and in wooded areas. They have also naturalized in a large portion of the western United States. Black-eyed Susans have been discovered in a few locations in China as well.

Brown-Eyed Susan vs. Black-Eyed Susan: How to Grow

The late summer to early fall blooming period of brown-eyed Susans produces beautiful cut blooms. After the last frost, brown-eyed susans can be immediately put in the garden or grown from seed started indoors in early April. Plant sets or seedlings should only be planted outside once the risk of frost has gone. To promote more blooms and discourage any undesired self-seeding, you can deadhead spent blossoms. The plant self-seeds, thus whether or not the original plant survives the winter can have little bearing on whether it will reappear in the spring garden. There are no significant pest or disease issues with brown-eyed Susans. However, mildew can occasionally affect it. Watch out for overabundant snail or slug populations on smaller plants. In USDA hardiness zones four through eight, brown-eyed Susans can thrive.

Black-eyed Susans are moderately tolerant of drought and forgive neglect. In ordinary, well-drained soil with full sun to moderate shade, this bloom develops quickly. Giving black-eyed susans full sun in good soil is the key to successful cultivation. The finest flower display will result from moderate fertility, therefore stay away from grass edges where lawn fertilizer would deliver too much nitrogen. There are no significant pest or disease issues with black-eyed Susans. However, mildew can occasionally affect it. Watch out for overabundant snail or slug populations on smaller plants. In the USDA hardiness zones three through eight, black-eyed Susans can be grown.

Brown-Eyed Susan vs. Black-Eyed Susan: Special Features

Bees, butterflies, and other pollinators are drawn to brown-eyed susans by the nectar and pollen in the blooms. Brown-eyed Susans can spread incredibly quickly if they are grown in a place where there are no competing species. During the growing season, brown-eyed susans can be quite bushy but showy in appearance.

Black-eyed Susans are excellent pollinators, just like brown-eyed Susans. Nectar from the blossoms attracts butterflies. The silvery checkerspot butterfly, which has one brood in the north and two broods from May through September in the rest of its habitat, and the wavy-lined emerald moth both use it as a host plant for their larvae. Black-eyed Susan seeds are also consumed by American goldfinches in the autumn.

These two plants do have some differences in hardiness zones, with black-eyed susans being the hardier of the two. If you live in hardiness zone three, we’d recommend planting black-eyed susans over brown-eyed susans. But at the end of the day, the brown-eyed Susan and black-eyed Susan are virtually identical plants. If you only plan on growing flowers for ornamental purposes, either one of these lovely flowers will do.

What is the Difference Between Black-Eyed Susans and Sweet Black-Eyed Susans?

Black-eyed Susans, much like brown-eyed Susans, are biennials, or short-lived and only live for a certain amount of time, while sweet black-eyed Susans (Rudbeckia subtomentosa) can live for many years. This sweet flower is a very hardy prairie plant and can survive, and thrive, in tough soils and is able to stand firm against high winds. They are typically located in areas that have certain habitats like wet prairies, or areas with a well-balanced supply of moisture, creek banks, savannas, and woodland borders.

Generally found in states that border the Mississippi, the sweet black-eyed Susan has flowers that start to bloom in late summer and continue through to fall and the leaves have a sweet scent that can be compared to sweet grass, which is how they earned their name, although the flowers have no scent.

The photo featured at the top of this post is © iStock.com/Dopeyden