The beautiful and versatile Rudbeckia species has many names, like “black eyed susan” or brown-eyed. This relative of the sunflower grows both wild in nature as well as it’s commonly cultivated by gardeners!
The difference between a black-eyed Susan and brown eyed ones is the color. A coneflower contains more seeds than other flowers, but it can also be infected with pests or diseases that only strike them.
I wanted to know if there were any differences in my garden so I read up on what might affect plants differently from each another!
The black eyed susan is a striking plant with many questions to answer. Let’s explore all there is about it and its close cousins!
Types of Black Eyed Susans
The black eyed susan is a common garden flower, and it’s easy to find in the four Rudbeckia species. The first three also cover many other variety that can be seen on both wildflower-rich fields as well as gardens all across North America!
Rudbeckia hirta, ‘Black-Eyed Susan’
This beautiful flower (Rudbeckia Hirta) is also known as the black-eyed susan. There are many varieties and cultivars of this particular species, such as Rudbeckia hirta var angustifolia (with narrow leaves), pulcherrima (‘most lovely’), floridiana (‘of Florida’). You can find it growing across most parts of North America into Canada!
This bright and beautiful flower is the perfect addition to any garden. The plant can be annual, biennial or perennial depending on its cultivar – it will grow anywhere from one inch up four inches in size with long yellow petals that extend outward form a black dome-shaped cone center.
The plant has leaves that are generally at the base of it and it seems like they’re covered in hair. The stems hold up blooms above them with thick petals sticking out all over! Some cultivars come in different colors, such as red or orange-brown shades for example.
Rudbeckia fulgida, ‘Rudbeckia Goldsturm’, ‘Orange Coneflower’, ‘Perennial Coneflower’, ‘Goldsturm Black-Eyed Susan’
Rudbeckia fulgida is a great variety for gardeners to choose from. With seven cultivars and two that have been honored by the Royal Horticultural Society, there’s sure to be one that will work well in your own space! This plant’s leaves are lance-like and covered in short hairs. On top of this, there is a tall stem with gold petals that bear out an oversized cone-shaped flower head at their centers.
Rudbeckia californica, ‘California Coneflower’
The California coneflower is a native plant of the north coast. It typically grows in moist environments near lakes, rivers and meadows around Mount Shasta or Klamath National Forest.
Looking for the perfect spot to plant your flower this summer? You’ll want something that will thrive in hot weather, like cosmos. This herbaceous perennial has dark green leaves and bright yellow petals surrounding its brown conic center stem which can grow up one meter high or more!
Rudbeckia triloba, ‘Browneyed Susan’, ‘Brown-Eyed Susan’, ‘Brown Eyed Susan’, ‘Thin-Leaved Coneflower’, ‘Three-Leaved Coneflower’
“Rudbeckia triloba is a plant that often grows in fields or along roadsides. It has larger flowers than other Rudbeckias, with three petals and colorful veining on the leaves.”
Black Eyed Susan Care
One of the best things about growing black eyed susan is that it’s incredibly easy to grow… sometimes even too easy, especially if you have a type which often grows in the wild.
Let’s go over some tips for not only planting this plant but also caring for and keeping them confined!
Light
Black eyed susans prefer an environment with full sun, although some varieties can also do well in partial shade. The more sunlight the better for this plant because it tends to flower better when given ample amounts of heat and light!
Water
While the black-eyed susan can tolerate some dry conditions, it prefers to grow in areas with regular watering. After all this plant tends to be found near rivers and meadows, but make sure the water is not standing, and provide good drainage.
Soil
Growing black eyed susans is easy with the right soil. A well-draining, but moist organic matter rich earth will produce plants of optimal health and growth.
While it can tolerate many different types from clay to sandy or even gravely terrain – these roots like their environment with plenty of air circulation around them while they’re still able to access fresh water at all times.
Fertilizer
You don’t want to overfertilize the soil, which causes drooping flower stems and weak growth. If you’re going to fertilize at all use a general purpose slow release granular fertilizer sparingly once or twice per year for best results.
In order to make the most of your garden, you should always enrich its soil with rich compost. Some wilder species don’t need fertilizer but they do appreciate some extra organic matter every now and then!
Propagating Black Eyed Susan By Division
Black-eyed susans can be a pesky weed, clogging up spaces and crowding out other plants. This is because their creeping roots spread far under the soil’s surface!
You’ll have to divide these perennials regularly or they may overpopulate your garden with vines that steal resources from their neighbors as well as nutrients from any flowers you were planning on planting in those spots next year too.
To divide black eyed susan, carefully scoop out the soil around its base and clear a wide enough area to remove it all at once. To start, dig 6-10 inches out from where you want it and slide in your trowel or shovel under all sides by gently levering away at dirt until there is enough space for planting again with roots exposed but not cut off (leverage means pushing down on one end).
Gently tease apart the root mass with your fingers and then use a knife that has been sterilized to start the cutting process.
For replanting, you want to have clumps of 3-5 tuberous roots with each pot containing both thick tubers and smaller ones. If reducing an existing plant’s size so it doesn’t crowd out its neighbors is what you’re after as well – this can be done easily enough by following these instructions!
Propagating Black Eyed Susan By Cuttings
Even though it’s possible to propagate by cuttings, black eyed susan tends not be as effective. Still if you want the same exact plant type of your original (as seeds can cause slight variations), this is still a great way!
The best, healthiest stems are those that have many leaves. These will give you the most roots! To take a cutting from one of these plants make sure to cut at an angle with about 6 inches long and leave only three uppermost leaves intact after dipping it in rooting hormone for placement into potting soil or composted bark mix.
To promote root growth, you need to keep the humidity up around your cuttings. You can do this by placing a plastic bag or other material over them and letting it retain moisture in order for roots to develop properly!
Propagating Black Eyed Susan By Sowing Seed
If you’re planting seeds in the spring, make sure your soil has reached at least 70 degrees Fahrenheit to offer best chance for germination. These plants will generally grow 1-3 feet tall and spread 12 -18 inches wide.
If you want to encourage a tighter and more compact growth pattern, the best way is by sowing your seed closer together. This will keep plants from spreading out too much or becoming messy with unattractive branches.
Gently sprinkle the seeds across your prepared soil’s surface. Once you place them, loosely cover with a thin layer of topsoil and water gently without washing away any covering dirt!
Problems When Growing Black Eyed Susan
The black eyed susan is a hardy plant with few growing problems, but it’s best to be prepared for anything. From garden pests and diseases that could attack your plants or cause them damage due to their position in the ground, even things like too much moisture can make this beautiful flower unhappy!
Pests
The two primary pests that prey upon black eyed susans are aphids and the cabbage worm. They’re also a plant that draws butterflies, which can be good as it adds another pollinator to your garden!
Prevent aphids with the use of neem oil, which will keep them at bay and prevent cabbage worms from hatching.
Be careful when you spray, because butterfly and moth populations could be affected by pyrethrins. It’s best to apply the chemical in late afternoon or early evening as these insects are at rest during those times of day.
Black-eyed susans are often a favorite amongst large livestock and wild animals alike, but they have an unpleasant flavor that drives off most creatures.
Diseases
Mildews are a huge problem to the plants in our garden. Black eyed susan is very susceptible, and can get sick from mildew or fungal diseases that come from watering too much!
Powdery mildew is an unfortunate side effect of too much humidity in the air. The best way to avoid this problem? Water plants properly, making sure that they’re always fully saturated before you let them dry out again! If your plant has already started developing powdery mildew, try wiping it out with neem oil, although this might not always be effective.
Downy mildew is a hard-to-eliminate type of fungus that often requires the application of an anti fungal agent such as liquid copper fungicide. A good option for this would be Bonide Copper Fungicide, which can treat both powdery and downy molds in addition to leaf spot diseases or any other types you may have on your plants!
The black eyed susan is also susceptible to a few leaf spot diseases. While the liquid copper fungicide mentioned above will help with some of these issues, it does not work on some particularly damaging types of fungus for this species.
The Septoria leaf spot is caused by the plant pathogen, and it causes dark spots to appear on your plants leaves. To combat this particular fungus that could be infecting you with its spores-you’ll need a fungicide that contains chlorothalonil like Bonide Fungil Oni lant sprays or Microlife Lotion Plus which both come in handy for treating different kinds of fungal infections!
Finally, verticillium wilt is a soil-borne disease that affects Rudbeckia. This fungal pathogen can easily be eliminated with fungicidal soaps or oils before planting in the area again to avoid any future problems! If plants are already affected, remove them and throw them away!