Black eyed Susan, Rudbeckia hirta, is a native wildflower of North America that belongs to the sunflower family (Asteraceae). It is widely recognized by its bright yellow petals and dark brown centers, which resemble the eyes of a person or animal. It is also a versatile and low-maintenance plant that can grow in various soil and light conditions, and attract many pollinators and birds to the garden. In this article, we will learn more about the black-eyed Susan plant, its characteristics, benefits, and drawbacks.
What is Black Eyed Susan?
Black-eyed Susan is a herbaceous perennial that reproduces both sexually and asexually by means of its seeds and creeping stems. The plant is erect or sprawling, and can reach up to 1 m (3 ft) in height and width. The stems are square, hairy, and sometimes reddish. The leaves are opposite, simple, ovate to lanceolate, and toothed. They are green, silver, or yellow, and have a variegated pattern of white or yellow spots or stripes. The flowers are tubular, two-lipped, and four-lobed. They are yellow, sometimes with brown or red markings, and have a hooded upper lip and a spreading lower lip. They are arranged in whorls or clusters, and bloom from late spring to early summer. The fruits are nutlets that contain one or two seeds.
There are several varieties and cultivars of black-eyed Susan, some of which have different flower colors, sizes, or shapes. For example, the ‘Jacob Cline’ cultivar has bright red flowers and mildew-resistant foliage, the ‘Marshall’s Delight’ cultivar has pink flowers and a strong fragrance, and the ‘Petite Delight’ cultivar has lavender-pink flowers and a compact habit. Some cultivars and hybrids are also more resistant to pests and diseases, such as powdery mildew and rust.
| Black Eyed Susan | Characteristics |
|---|---|
| Scientific name | Rudbeckia hirta |
| Common name | Black eyed Susan, wild bergamot, horsemint, Oswego tea |
| Plant type | Herbaceous perennial |
| Mature size | 30 to 100 cm (12 to 39 in) tall and wide |
| Sun exposure | Full sun to partial shade |
| Soil type | Well-drained, moist, rich |
| Soil pH | Slightly acidic to neutral (6.0 to 7.0) |
| Bloom time | Late spring to early summer |
| Flower color | Yellow, red, pink, purple, white, or multicolored |
| Flower shape | Tubular, two-lipped, four-lobed |
| Foliage color | Green, silver, or yellow |
| Foliage shape | Opposite, simple, ovate to lanceolate, toothed |
| Hardiness zones | 3 to 9 (USDA) |
| Native area | North America |
How to Grow Black-Eyed Susan?
Black eyed Susan is an easy and adaptable plant that can grow in almost any garden. It can tolerate a range of soil and light conditions, and can survive drought, frost, and pests. It can also self-seed and spread by rhizomes, making it a good choice for naturalizing or filling large areas. However, it can also become invasive or aggressive in some situations, so it is important to control its growth and prevent its escape.
To grow black eyed Susan, you can either start from seeds, cuttings, or divisions. Seeds can be sown indoors in late winter or early spring, or outdoors in late spring or early summer. Cuttings can be taken from young stems in spring or summer, and rooted in moist soil or water. Divisions can be done in spring or fall, by digging up the clumps and separating them into smaller pieces. You can also buy black-eyed Susan plants from nurseries or garden centers, and transplant them to your desired location.
Black-eyed Susan prefers a sunny spot with well-drained, moist, rich soil, but it can also tolerate some shade and poor soil. It does not need much water or fertilizer, as it can thrive in natural conditions. However, it may benefit from some mulch to retain moisture and suppress weeds, and some compost or organic fertilizer in the spring to boost its growth and flowering. It can also be deadheaded to prolong its blooming period and prevent self-seeding, and pruned to remove any dead, diseased, or damaged leaves and flowers.
How to Use Black-Eyed Susan?
Black eyed Susan, a versatile and beloved plant, serves multiple purposes in gardens and landscapes. Whether you’re cultivating a wildflower meadow, designing a cottage garden, or enhancing your borders and rock gardens, this plant is a top choice. Its striking flowers and foliage can provide a beautiful contrast to other flora, complementing various shapes and textures. Moreover, Black-eyed Susan can thrive in containers, hanging baskets, and window boxes, adding a touch of natural beauty to urban settings. Beyond its ornamental value, some gardeners even use it as a cut or dried flower for floral arrangements. While discussing the versatility of this plant, it’s essential to remember its ecological significance, as it can also attract beneficial wildlife, such as pollinators. In addition to Black-eyed Susan, other native plants like wild ginger can further enhance the ecological balance and diversity of your garden.
Black eyed Susan is also a useful plant for wildlife, as it provides food and shelter for many insects, birds, and small mammals. It is especially attractive to bees, butterflies, and other pollinators, which visit the flowers for nectar and pollen. It can also host some caterpillars, such as those of the wild indigo duskywing (Erynnis baptisiae) and the frosted elfin (Callophrys irus). The seeds and leaves can be eaten by some birds, such as cardinals, quails, and sparrows, and the plant can also offer cover and nesting material for them. Moreover, the plant can help to prevent soil erosion and improve soil quality, as it has a deep root system and can fix nitrogen.
Black eyed Susan is also a medicinal plant, as it has been used for various ailments in traditional medicine. It has anti-inflammatory, antiseptic, antispasmodic, and laxative properties, and can be used to treat skin problems, such as boils, ulcers, or wounds, respiratory problems, such as cough, asthma, or bronchitis, digestive problems, such as constipation, diarrhea, or indigestion, and nervous problems, such as insomnia, anxiety, or headache. It can also be used to reduce fever, pain, swelling, and bleeding. The leaves, flowers, roots, and seeds can be made into a tea, a decoction, a tincture, or a poultice, and applied externally or internally as needed. However, it is advisable to consult a doctor before using black-eyed Susan for medicinal purposes, as it may have some side effects or interactions with other drugs.
Black eyed Susan is also a culinary plant, as it has a minty and citrusy flavor that can be used as a herb or a spice. It can be added to salads, soups, stews, sauces, jams, or desserts, or used as a garnish or a seasoning. It can also be used to make vinegar, wine, liqueur, or candy. The leaves and flowers are edible, but they should be used sparingly and fresh, as they can lose their flavor and become bitter when dried or cooked. They should also be harvested before the plant blooms, as they can become more bitter and less aromatic after flowering.
How to Control Black-Eyed Susan?
Black-eyed Susan is a plant that can be both a friend and a foe, depending on where and how it grows. It can be a hardy and beautiful plant in some situations, but it can also be a nuisance and a threat in others. It can be invasive or aggressive in places where it is not native or wanted, such as lawns, pastures, crops, or natural areas. It can spread rapidly and densely, and block the sunlight, oxygen, and water flow. It can also displace or compete with other plants and animals, and reduce the biodiversity and productivity of the ecosystem. It can also be difficult to eradicate, as it can regenerate from any part of the plant that is left behind.
Therefore, it is important to control black eyed Susan if it becomes a problem in your area. There are several methods that can be used to do so, such as:
- Manual removal: This involves pulling, digging, or mowing the plant by hand or with tools, and disposing of it properly. This can be effective for small infestations, but it can also be labor-intensive and time-consuming. It is also essential to remove all parts of the plant, including the roots and rhizomes, and to repeat the process regularly until no more growth is observed.
- Chemical control: This involves applying herbicides to the plant, either by spraying, wiping, or injecting. This can be effective for large infestations, but it can also be costly and harmful to the environment and other plants and animals. It is also important to choose the right herbicide for the situation, and to follow the instructions and precautions carefully.
- Biological control: This involves introducing natural enemies of the plant, such as insects, fungi, or animals, that can feed on or damage the plant. This can be effective for long-term control, but it can also be risky and unpredictable. It is also important to ensure that the introduced agents are specific to the target plant, and that they do not cause any unwanted impacts on the ecosystem.
Frequently Asked Questions
Here are some of the most common questions and answers about black eyed Susan:
- How to propagate black-eyed Susan?
Black eyed Susan can be propagated by seeds, cuttings, or divisions. Seeds can be sown indoors in late winter or early spring, or outdoors in late spring or early summer. Cuttings can be taken from young stems in spring or summer, and rooted in moist soil or water. Divisions can be done in spring or fall, by digging up the clumps and separating them into smaller pieces. You can also buy black-eyed Susan plants from nurseries or garden centers, and transplant them to your desired location.
- How to care for black-eyed Susan?
Black eyed Susan is a low-maintenance and drought-tolerant plant that does not need much water or fertilizer, as it can thrive in natural conditions. However, it may benefit from some mulch to retain moisture and suppress weeds, and some compost or organic fertilizer in the spring to boost its growth and flowering. It can also be deadheaded to prolong its blooming period and prevent self-seeding, and pruned to remove any dead, diseased, or damaged leaves and flowers.
- How to prune black-eyed Susan?
Black-eyed Susan does not need much pruning, as it has a natural and graceful shape. However, it can be pruned to remove any dead, diseased, or damaged leaves and flowers, and to shape and rejuvenate the plant. Pruning should be done after flowering, usually in late summer or early fall. Pruning should be done with sharp and clean tools, and about one-third of the old stems should be cut back to the ground. Any crossing or crowded branches should also be thinned out to improve air circulation and light penetration.
- Is black-eyed Susan poisonous?
Black eyed Susan is not poisonous to humans, but it can be toxic to some animals, such as cats, dogs, and horses. The plant contains essential oils, such as thymol and carvacrol, which can cause symptoms such as vomiting, diarrhea, drooling, depression, and skin irritation. The flowers are especially toxic, as they can cause severe gastrointestinal upset and liver damage. Therefore, it is advisable to keep the plant away from pets and livestock, and to wear gloves when handling the plant. If you suspect that your animal has ingested the plant, you should contact your veterinarian immediately.
- How to grow black-eyed Susan from seed?
To grow black eyed Susan from seed, you can either sow the seeds indoors in late winter or early spring, or outdoors in late spring or early summer. If you sow the seeds indoors, you will need to use a seed tray or a pot with drainage holes, and fill it with moist and sterile potting mix. You can sprinkle the seeds on the surface of the soil, and lightly cover them with a thin layer of soil or vermiculite. You can place the tray or pot in a warm and bright location, such as a windowsill or under a grow light, and keep the soil moist but not soggy. You can expect the seeds to germinate in about two to three weeks, and you can transplant the seedlings to larger pots or outdoors when they have at least two sets of true leaves. If you sow the seeds outdoors, you will need to choose a sunny spot with well-drained, moist, rich soil, and prepare the soil by removing any weeds, rocks, or debris. You can scatter the seeds on the surface of the soil, and lightly rake them in. You can water the area well, and keep the soil moist until the seeds germinate. You can thin out the seedlings to about 30 to 45 cm (12 to 18 in) apart, and mulch around them to retain moisture and suppress weeds. You can expect the plants to flower in the first or second year, depending on the variety.