Black-eyed Susans are a beautiful and easy-to-grow flower from the Asteraceae family. They tend to spread quickly. Black-eyed susan grow everywhere on the east coast, from Newfoundland to Florida. They have also adapted well to the West Coast and have grown from British Columbia to Ba California They were used as herbal medicine to treat colds and infections by Native Americans and were introduced to European gardens in the 1700s.
They are usually grown as ornamental flowers. They are quite cute, with characteristic black balls in the center and yellow petals that spread all around. There are some varieties, even some with flowers of different colors. Black-eyed Susan range in size, from one foot to three feet tall. The smallest flowers, about 3-4 inches in diameter, are often best for growing in pots because they are plants with deep roots. Some are quite large, such as the Indian summer, which is often on the order of three feet tall, and the flowers are up to 9 inches in diameter! They can be used to illuminate the boundaries of your garden in the summer or as a fireplace in a flower bed.
Rudbeckia hirta (biennial), Rudbeckia fulgida (perennial)
Grown as annual, biennial and perennial.
Full sun
Fertile, well-drained neutral soil (pH 6.8-7.7)
Start seeds in autumn or spring
Plant in the garden
Plant 6-12 “apart (8″ apart is a good rule of thumb for smaller varieties)
Plant 18-24 ” apart for larger perennials.
Growing in containers:
Start individual plants in a large pot, at least a gallon, the more the merrier
Ensure good drainage
Water new plants regularly, when the soil is dry. Established flowers do not need excessive watering.
Climatic zones 4-9 (Some varieties are hardy in zone 3)
There are two main groups of black-eyed Susan. Biennial types are Rudbeckia hirta and are usually smaller. They are technically short-lived perennials, rather than biennials, but it is easier to consider them as biennials. They are most often grown as annuals. Perennial types with a longer lifespan are Rudbeckia fulgida, and these are usually larger. Some varieties can last up to 15 years. There are also some related similar plants. The first is Rudbeckia laciniata, usually called “Cut-leaf Echinacea” because they have a multicolored cone instead of the black globe typical of black-eyed Susans. Another is Rudbeckia subtomentosa ” Sweet Echinacea.”Sweet Echinacea has narrower petals than black-eyed Susans. For both, planting and care are like the perennial types of black-eyed Susan. As a side note, the black-eyed Susan vine, Thunbergia alata, is an unrelated drink plant with similar-looking flowers growing in heat subtropical and tropical climates.
Planting Black-eyed Susani
Black-eyed Susan are usually grown from seedlings, but they can also be started directly into the garden from seeds. Timing is important for planting. Black-eyed Susan should be planted in the garden in the spring after the last frost, or in the fall at least six weeks before the first frost. It is often preferable to plant in the fall, which allows the plant to overwinter, which will produce a regular supply of flowers the following summer. They can be grown as annuals, but for this it is better to start biennial varieties about six weeks before the last frost, to allow additional growth, and then transplant them into the garden after the last frost. This gives the plant enough time to mature to bloom in the first year.
Plant seeds or seedlings for small flowers about 8 inches apart, but larger varieties need more space. For these, 18 inches away is a good distance, as root systems can get quite large. Choose a place that gets full sun, if you can. Dig a hole a little larger than the plant and fill it with good garden soil. They grow best in well-drained soils. Larger plants can be planted closer to each other. If so, proximity will reduce the rapid spread of the plant over the years, but may encourage some health issues and pests. It is better to water them regularly, but water flush with the soil than to spray water over the plants.
Growing conditions for Black-eyed Susans
These flowers are very hardy! They can withstand hot and cold temperatures, as long as they are heat than the Arctic or subarctic and cooler than the tropics. Seedlings need heat temperatures until they have some growth and some roots are established. Once started, they overwinter well in sub-zero temperatures and will return immediately in spring. They love the light! Full sun is important. They can survive in a light shadow, but the more light, the better.
These flowers are also perfect for containers. They need big pots! Root systems are large enough and need enough space. For smaller flowers, a gallon-sized vase will do, but the bigger the better. It is easier to grow smaller types in pots, as this allows you to easily control the soil, water and light. Fertilization is usually not necessary for this versatile flower. Keep the soil moist by watering regularly (even daily). Make sure that the pots drain very well and that the soil is never soggy, only moist. Larger perennials will also do well in pots, but the pots should be even larger. Potted earth can become colder than ground earth in winter. In colder climates, it may be best to move them indoors in winter, to prevent the soil from freezing. Usually, an unheated basement or garage will be suitable for this.
