If you are looking for a bright yellow, orange or bronze daisy to bob its cheerful head in your garden, you won't do much better than to plant a rudbeckia -- also known as black-eyed Susan, brown-eyed Susan, conedisk, conedisk sunflower, tall coneflower, gloriosa daisy and rudbeckia.
Famed botanist Carl von Linne, better known as Carl Linnaeus, gave this group of plants the name of rudbeckia to honor his botany professor, Olaf Rudbeck whose father founded the botanical garden at Uppsala University in Sweden. Linnaeus told Rudbeck that "so long as the earth shall survive, and each spring shall see it covered with flowers, the rudbeckia will preserve your glorious name."
Apparently Linnaeus' plan worked, because although most of us know nothing about Olaf Rudbeck or his father's botanical garden, we do know about the beautiful rudbeckias.
Common names are unreliable as they can refer to any of a number of plants depending on where you live. You would do best to ask for rudbeckia it by its Latin name. All are native to North America and grow wild from Canada to Mexico in the East and Midwest in fields and gardens.
Native Americans used these flowers as herbal medicines for both people and horses. They made tea and compresses of the roots and flowers to treat a variety of ailments including snake bites, worms, earaches, indigestion, burns and sores.
These daisy-type flowers may be single, semi-double or fully double with rich, lemon-yellow, gold, chestnut, mahogany and bronze flowers set off by coarse-textured, hairy green leaves. They appear from mid-summer to fall.
You have a wide range of flowers to choose from among the 25 species of rudbeckia, which can be perennials, biennials and annuals. They may be tall or short, or even miniatures. You may have to look a little for some of these as not every nursery will devote space for all 25.
Use them in perennial beds, mixed borders and containers, alone, in mass plantings, as a border, or along a fence. If you like butterflies and bees, rudbeckias are a good choice. They attract bees and butterflies to the flowers and ripe coneheads provide seed in fall and winter for birds.
Rudbeckia hirta, often called gloriosa daisy, is the largest group of these favorites. They bloom from July until frost in shades of orange, yellow and orange-yellow. It is a short-lived perennial in mild climates, but will likely be an annual here in Utah. The variety 'Indian Summer' is an All-America Selections (AAS) winner from 1995. It takes center stage with its bright 5- to 9-inch blossoms on plants reaching 3 feet tall.
At 30 inches tall, another AAS winner, 'Cherokee Sunset, Rudbeckia x hirta hybrida, produces semi-double and double flowers 2 to 4 inches across in shades of yellow, orange, bronze and mahogany.
If you prefer a biennial or short-lived perennial, try brown-eyed Susan, rudbeckia triloba, which is hardy to zones 4-7. It grows 2 to 5 feet tall depending on growing conditions and produces an abundance of 1- to 2-inch yellow flowers around black centers that fade to brown.
Rudbeckia laciniata, cutleaf coneflower or ragged coneflower, is another perennial. You are most likely to find the old-fashioned heirloom 'Golden Glow,' that grows 8 to 9 feet tall with yellow double flowers and deeply cut leaves. Give it space -- it may spread to as much as 6 feet across.
Rudbeckia fulgida produces warm yellow flowers on 2- to 3-foot-tall plants. The variety sullivantii 'Goldsturm', or Golden Storm, is a perennial that provides masses of flowers with pale gold petals from midsummer through September. They are very hardy from zones 3-9, and grow 2 to 3 feet tall.
If you are limited on space, you may not want the large varieties listed above. Look for dwarf varieties like 'Becky' which grows 10 to 12 inches tall with 3-inch flowers in orange, yellow and cinnamon bicolor. You may find these in a formula mix.
'Toto' is another dwarf with smaller flowers on 12- to 15-inch tall plants. These too may come in a variety of colors in a mix. Look also for 'Corona,' 'Cordoba,' 'Sonora,' and the fully double 'Maya,' for containers and small spots.
The name "Black-eyed Susan" doesn't apply as well to the 2003 AAS winner 'Prairie Sun,' since it produces a light-green center cone surrounded by golden-yellow petals tipped with lighter primrose yellow around a light-green center cone. It grows 3 feet tall and is well adapted to gardens and large containers. Look for a similar variety with smaller yellow flowers and green centers aptly named 'Irish Eyes' or 'Green Eyes.'
One unusual rudbeckia called rudbeckia occidentalis 'Green Wizard,' would provide a great contrast to the bright colors of the garden. These don't produce petals, just a tall black cone center with green sepals around it. The cone center makes a delightful addition to fresh or dried arrangements.
If you are new on the gardening scene, you will probably like raising rudbeckia. They are easy to grow in average soil, require little maintenance, don't mind fairly dry conditions, and come in a range of sizes, shapes, colors and forms. Choose a sunny spot if you can to get the most blossoms. However, it will tolerate light shade, producing fewer flowers.
These plants are also deer-resistant -- a real plus if these browsing animals have found your yard. As young plants they are susceptible to slugs and snails.
Direct seed them or for earlier blossoms, put in transplants. You can plant perennial varieties in the fall or spring and they will bloom the first year if you start them early. Space them according to variety and mature size.
To encourage extended flowering, remove or deadhead faded flowers at the base of the flowers stems. Leave the blossoms on to go to seed to attract birds. These plants often self-seed so you may find them popping up around the gardens. They are easy to remove, however. Pluck them up and they are gone.
Perennial rudbeckias do not need regular division but you can divide them if you want to move crowded plants or spread them over more of your garden. Divide in early spring just as growth begins to develop. They naturalize easily and won't require a great deal of attention.
These lovely plants have another bonus. They stay fresh and colorful for up to 21 days after they are cut. The dried coneheads add an interesting shape and texture to everlasting arrangements and crafts. Grow them in a cutting garden with purple coneflower and Shasta daisy.
Few insects or diseases bother these plants, but you may have problems with powdery mildew on the leaves. Minimize this by planting in a sunny area and allow enough growing space for good air circulation.
Thanks to the National Garden Bureau for providing the information on this flower.