It’s not hard to see why Black-Eyed Susans, or Rudbeckias are so popular. They add rays of color to any garden, and attract beneficial insects, which benefit all of your plants.
While they are found as wildflowers in the United States, they are grown and admired all over the world for their beauty. They also have the satisfaction of being a flower that’s very easy to grow.
They’ll bloom all summer long, and depending on the type, they will also spread to fill borders or containers with a wealth of color. In colder climates, they will disappear during the winter, and you’ll see them spring back to life in summer.
Read on to discover more about the black-eyed Susan, how you can grow this plant, and the symbolism behind it.
Where does the ‘Black-Eyed Susan’ Come From?
The name ‘Black-Eyed Susan’ refers to the flower’s dark ‘eye’ at the center of the flower, contrasting the bright petals.
You may be wondering who Susan is. The name also refers to an Old English poem by John Gay, named ‘Sweet William’s Farewell to Black-Eyed Susan’.
Susan searches the docks for her lover William, before he goes off on a very long journey as a sailor.
The name ‘black-eyed’ comes from the dark circles around her eyes from crying. The poem is his farewell to her.
‘Sweet William’ is another term for Dianthus barbatus, which blooms at a similar time to the ‘Black-Eyed Susan’.
To some people, this represents the eternal love between Susan and William.
The identity of Sweet William and who that may represent outside the poem is widely disputed. Suggestions range from William Augustus, the Duke of Cumberland, William Shakespeare, or William the Conqueror.
The Meaning Behind the Scientific Name
This plant is also known as Rudbeckia, which is an entire genus of flowers. The common name also refers to all specific types of Rudbeckia such as Rudbeckia hirta interchangeably, just to make things more confusing.
Carl Linnaeus gave the genus the name Rudbeckia in honor of his colleague, Olof Rudbeck, who was a botanist at Uppsala University. The name also honors his father, Olof Rudbeck the Elder, who discovered the lymphatic system.
The name hirta is derived from the Latin word hirtus, which means hairy. This describes the leaves and stems of the species.
Other common names include the coneflower, the golden Jerusalem, the yellow daisy, English bull’s eye, and the gloriosa daisy.
The Difference Between a Black-Eyed Susan and a Black-Eyed Susan Vine
Several plants share common names, and this is the same for the Rudbeckia and Thunbergia alata (see also Flower Names Starting With T), which share the name black-eyed Susan.
The most obvious difference is the way they grow. The black-eyed Susan vine grows as a climbing plant which needs a lot of support, while Rudbeckia is a flowering plant that grows upright, and rarely needs staking.
You can also tell the difference in the flowers. The central eye of a Rudbeckia consists of tiny florets which form a vague cone, while the vine’s flowers have nearly tubular centers. The black-eyed Susan vine also has tubular blooms with overlapping petals.
Historical Uses of the Black-Eyed Susan
While Rudbeckia is primarily grown for its ornamental value, it’s also been used in medicine throughout history, notably by Native Americans.
They used different parts of the plant to treat earaches, parasitic worms, and snakebites, making it a versatile plant which has more to it than meets the eye.
Rudbeckia is also a great butterfly magnet, as well as being beneficial for all kinds of pollinators. Black-eyed Susans are also toxic to cats if ingested.
How to Recognize a Black-Eyed Susan
Rudbeckias come in many forms, and this is also true of Rudbeckia hirta, which comes in biennial, annual and perennial types.
Some are taller than others, but most reach nearly 3.5 feet high. Taller varieties need to be planted somewhere sheltered, where the wind can’t break the stems.
The leaves are deciduous, which means that they drop when the temperature falls in autumn. In colder climates, hardier rudbeckias will shrink to the safety of the soil, and will come up again in late spring and early summer.
The leaves have a rough texture to the touch, and they can be lance head-shaped, or egg-shaped, depending on the species. They can range from 5 to nearly 18cm long.
The color depends on the variety, but they come in a whole range of hues, some of which are bicolored. The most well-known of course is the golden yellow, but they are also found in red, burgundy, and orange.
The eye of the flower is usually brown, but some species feature green centers. The flowers can grow in corymbs (clusters on the same stem, where the youngest flower forms at the center) or one flower per stem.
Rudbeckia seeds are small, which are coppery brown and elliptical.
Black-Eyed Susan Varieties and Cultivars
All Rudbeckias are part of the Asteraceae genus, or the daisy family. Rudbeckia hirta plants hail from North America, and are divided into four varieties, which are listed below. They are found in different parts of North America.
Rudbeckia hirta var. Angustifolia
Native to Texas and southeastern America, Rudbeckia hirta var. Angustifolia grows in abundance in meadows, fields, and at the side of roads as wildflowers.
Rudbeckia hirta var. Floridana
This variety of Rudbeckia hirta comes from Florida, like the name suggests. It comes in perennial, biennial, and annual forms, and is commonly found in pastures and fields.
Rudbeckia hirta var. Hirta
The woodland black-eyed Susan or the Hirta variety of Rudbeckia hirta (see also Rudbeckia Guide) grows in open woods, roadsides, and woodland clearings, in the eastern United States.
Rudbeckia hirta var. Pulcherrima
This is the most wide-spread variety of Rudbeckia in its natural habitats of disused fields and roadsides. It’s found growing wild in nearly all parts of North America except Nevada and Arizona and Southern Canada.
Popular Black-Eyed Susan Cultivars to Grow in Your Own Garden
The combination of the widespread popularity and the relative ease in which Rudbeckias can be hybridized has meant that there are a huge number of varieties which we’ve created over the years. Below are some of the most eye-catching cultivars.
Rudbeckia hirta ‘Autumn Colors’
This variety produces beautifully golden flowers with hues of red, bronze, and rust. It can spread to a maximum of 18 inches, and up to 24 inches high.
Rudbeckia hirta ‘Cappuccino’
These lovely half-hardy annuals grow to a maximum of 24 inches high, and spread to 12 inches.
This fantastic variety features a plethora of large blooms with petals in mahogany and orange tips, and an eye ringed with yellow.
Rudbeckia hirta ‘Cherokee Sunset’
While usually grown as an annual, you can also overwinter ‘Cherokee Sunset’ in colder climates. It produces better flowers in its second year.
Blooms feature a captivating rusty palette, and do well both in borders and as cut flowers.
Rudbeckia hirta ‘Cherry Brandy’
If you’re sick of golden-rayed rudbeckias (is there such a thing?) and you want something different, ‘Cherry Brandy’ is the one to go for.
The petals often curl up at the outer edges, making for a stunning bloom which stands out in any display you can think of.
Rudbeckia hirta ‘Chim Chiminee’
A captivating gold and mahogany colored flower, this rudbeckia features very thin, spindle-like petals that are no-less beautiful than other varieties.
It makes a fantastic cut flower, and like most rudbeckias, it needs full sun. This variety produces flowers with the occasional double flower.
Rudbeckia hirta ‘Sahara’
Like most Rudbeckias, ‘Sahara’ will grow in most soil types, as long as the soil can drain freely, and it’s in a position to get the most amount of light possible.
Like the name suggests, these flowers come in a range of colors that remind you of the desert. Yellows, russet browns, and reds all make a lovely display.
Rudbeckia hirta ‘Russet Glow’
If you’d prefer a rudbeckia with narrow petals, ‘Russet Glow’ is a nice choice. The blooms come in a rich cinnamon, with very large globular centers which are tinged with yellow.
These striking blooms will make a great companion plant and contrast to any large flower that you can think of. For a large display, plant at least three in succession with plenty of space in between to allow them to spread.
These lovely flowers will create a display from August until September.
How to Grow Black-Eyed Susans
Rudbeckias are very easy plants to grow, and will reward you with a plethora of colorful blooms all summer long.
They are favorites of seasoned gardeners and beginners alike, for their ornamental value as well as how easy they are to grow.
To get the most out of these plants and maximize the quality and number of flowers each plant will produce, there are a few steps to follow.
You have a number of choices when it comes to growing black-eyed Susans. You can try growing them from seed, if you have the room and a warm, sunny space for them to germinate.
For best results, always follow the advice on the seed packet. To stop a green bloom from forming on the soil and preventing the seeds from sprouting, lightly cover the surface with horticultural grit. Don’t worry, the seedlings will make their way through just fine!
Rudbeckia seeds require a minimum temperature of 68°F in order to germinate, and will sprout anywhere from 8-14 days after you’ve sown the seeds.
If you’d prefer to grow plugs or established plants, these are readily available from most garden nurseries or anywhere else that sells plants.
Whichever form you choose, young plants need to be watered well in order to establish properly.
Once they are mature, and they are settled into their new environment, watering them once a week is usually plenty.
As these plants have a wide spreading habit, you should place individual plants at least 12 inches apart to give them room to bloom.
Care and Maintenance
While Rudbeckias love full sun for as long as they can get it, they will also brighten up areas of partial shade.
These plants aren’t fussy about soil type, and they’ll grow in pretty much anything.
They are also drought-tolerant, which makes them a favorite choice for those who want to water their gardens less, or for those who are climate-change conscious when it comes to their planting choices.
Rudbeckias will also handle some salt in the soil, where other flowers will wilt pretty much immediately.
Fertilizer is only really beneficial during the flowering months to encourage healthy growth.
It’s very easy to overfeed plants and tip the nutrients in the soil out of balance. This can lead to imbalances in the way the plant grows, but it’s easily prevented.
To encourage more blooms, you can deadhead the faded flowers. The plant will spend less energy trying to create seeds, and it will put more energy into producing flowers.
The plant itself doesn’t need cutting back at any stage, as the foliage takes care of itself.
It is recommended though to cut off any leaves or parts of the plant which have been affected by disease, to stop it spreading to the rest of the plant.
Pests and Diseases
Aphids and powdery mildew are the worst blights to plague black-eyed Susans.
You can recognize powdery mildew by yellowing leaves and eventually, they will fall from the plant.
Powdery mildew thrives in humid conditions without proper ventilation. Keeping rudbeckias in full sun will also help limit the potential hold this disease can have.
Young rudbeckia plants are tasty snacks for deer, so prepare accordingly.
Rudbeckia plants are also vulnerable to rusts, stem rot, fungal leaf spots, and aster yellows.
Meaning and Symbolism
In April 1918, Rudbeckia became the official state flower of Maryland. It’s often planted to celebrate the people who live in Maryland.
The flower itself symbolizes joy, motivation, and is used as a message of encouragement. It also represents resilience and survival, as these beautiful plants will grow in a range of environments.
These flowers are perfect gifts for numerous occasions. They are great flowers for adding a wealth of positivity to someone’s day, making them a nice way to help cheer someone up.
Gifting someone a rudbeckia as a plant instead of a cut flower or as part of a flower arrangement is a good idea for someone who is just getting into gardening, as they are easy to look after.
They also have a relatively longer life as a cut flower than other popular blooms.
They’re also a great “just because” gift.