Rudbeckia

( rud - BEK - ee - uh )

At-A-Glance Information

This genus of perennial and biennial flowering plants is commonly called Black-Eyed Susan or Coneflower, and includes species which need full sun and moderate to regular water to perform well in the garden. Their flowers will attract birds, butterflies, and other beneficial insects to the landscape. They have large, yellow flowers that are commonly used in fresh arrangements arrangements. Blooms are present in summer and fall. Use Rudbeckia in the landscape in mass plantings or meadows, in mixed borders and beds, or in pollinator gardens.

Rudbeckia Species and Varietals

The genus Rudbeckia is a member of the plant family Asteraceae and includes around 25 species. Rudbeckia grows well in USDA hardiness zones 3-9 or Sunset growing zones 1-24, though this varies depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Rudbeckia californica (California Coneflower, California Rudbeckia, California Cone Flower)
These flowers are native to California and prefer to grow in moist habitats, like streambanks and meadows. The species forms an erect perennial plant with green basal foliage. Flowering stems support solitary yellow blooms with brown protruding centers. This species reaches between 3 and 6.5 feet tall when in bloom and grows well in USDA hardiness zones 6a-9b.

Rudbeckia fulgida (Orange Coneflower, Perennial Coneflower, Black-Eyed Susan, Shining Coneflower, Perennial Black-Eyed Susan)
This perennial reaches 3 feet tall and 2 feet wide, and has branching stems and dark green, hairy foliage. Flowers are yellow with a dark central cone, and bloom in summertime. Cultivars include 'Early Bird Gold' (with a longer blooming period), 'Little Gold Star' (to 16-18 in. good for containers), 'Glitters Like Gold' (to 2 feet tall with leaf spot resistance) and 'Goldsturm' (with yellow flowers that have black eyes on 2.5 foot tall stems).

Rudbeckia hirta (Gloriosa Daisy, Black-Eyed Susan, Black Betty, Golden Jerusalem, English Bull's Eye, Poor-Land Daisy, Yellow Daisy, Yellow Ox-Eye Daisy)
This species of is a biennial or short-lived perennial that is often grown as an annual. Flowers are orange-yellow and a prominent purple-black central cone. These flowers are known to attract bees. Cultivars are outlined below:

'Autumn Colors'
Muticolored flowers marked with red, gold, bronze and yellow hues. To 18-30 in.

'Cherokee Sunset'
2-2.5 feet tall with double or semi double blooms in gold with deep red centers.

'Cherry Brandy'
Unique deep cherry red flowers with dark brown centers.

'Denver Daisy'
2 feet tall and 18 inches wide. Yellow with painted red-brown centers.

'Goldilocks'
Double blooms on a plant that reaches 8-10 inches tall.

'Indian Summer'
Single to semidouble golden yellow flowers.

'Irish Eyes' ('Green Eyes')
Yellow flowers with a green central cone. To 2-3 feet tall.

'Marmalade'
Dwarf to 1-2 feet tall with gold-orange daisy flowers.

'Prairie Sun'
Golden yellow flowers with pale yellow tips and a light green central cone.

'Tiger Eye'
16-24 inch tall plant with profuse blooms.

'Toto' Series
14 inch tall plants with lemon, gold, or rustic-red flowers.

Rudbeckia laciniata (Cut-Leaf Coneflower, Green Headed Coneflower, Goldenglow, Sochan, Thimbleweed)
Cut-Leaf Coneflower is native to a large region in North America and and can reach 10 feet tall and 4 feet wide, and has light green leaves. Blooms pop in summer and last through fall and are yellow with a light green cone. Cultivars include 'Goldquelle' (with double blooms to 3-4 feet), 'Herbstsonne' (also called 'Autumn Sun', reaching 5-7 feet tall and 2 feet wide, with prominent green-yellow cones), 'Hortensia' (also called 'Golden Glow', heirloom with double gold flowers with reduced cones) and 'Starcadia Razzle Dazzle' (with good garden performance and light yellow flowers). This species is considered invasive in Europe, Central and East Asia, and Indonesia.

Rudbeckia occidentalis (Western Coneflower)
This species of Coneflower is native to the northwestern United States, where it prefers to grow in moist habitats, such as meadows. It is suited for growing in USDA hardiness zones 3-10. These erect perennials form from a thick rhizome and produce an unbranched stem reaching about 6 feet tall when in bloom. Flowers are rayless, and centers are purple-brown, packed with small blooms. Cultivars of this species include 'Green Wizard' (to 3-5 feet) and 'Black Beauty' (to 2-3 feet tall).

Rudbeckia triloba (Brown-Eyed Susan, Thin-Leaved Coneflower, Three-Leaved Coneflower, Branched Coneflower, Three-Lobed Coneflower)
This species is perennial and reaches 3-5 feet tall and 2.5 feet wide, with yellow flowers that have brown centers. They will reseed freely in the garden. These plants are widely cultivated in gardens, and are easy to grow when provided with full sun and moist soil. Cultivars include 'Prairie Glow' (with burnt orange-red and yellow flowers with dark black centers; 3-4 feet tall), and 'Blackjack Gold' (compact to 3 feet tall with an upright habit and yellow petals).

Caring for Rudbeckia

Plant Rudbeckia in a spot in the garden that gets full sun. They like to receive between 6 and 8 hours of sun each day, but can also handle partial shade. In warmer climates, make sure they get some late afternoon shade when temperatures are at their peak (typically between 2 and 3 PM). Ensure that soil is well-draining, moderately fertile, and with a pH of between 6.5 and 7.0 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish themselves in the landscape. At maturity, Rudbeckia plants are considered to be drought-resistant, able to get by on rainwater alone for most of the year with supplemental waterings during periods of dry weather.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flowers to neaten up the appearance of plants and encourage reblooms. Divide perennial Rudbeckias every few years when the plants become crowded and performance suffers. For instructions on how to successfully divide these plants, consult the Propagation section below. Rudbeckia plants can be annual, biennial, or perennial depending on the species cultivated and the climate it is grown in. Annuals are typically pulled and composted at the end of the growing season and replaced in the next with new flowers. Biennials are treated similarly, and are replaced after flowering ends. True perennial species form clumps that can reliably persist for a few years to a decade or more in the landscape before needing to be replaced.

Caring for Rudbeckia in Containers
Rudbeckia shrubs are wonderful in the ground, but can also be grown in containers. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Rudbeckia plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Harvesting Rudbeckia
Rudbeckia makes a cheerful cut-and-come-again addition to cut flower gardens, and are used as focal points or anchors in arrangements and bouquets. They are valued for their tall, strong stems and long vase life. The most common varieties grown for cut flowers includes Rudbeckia hirta 'Indian Summer' and 'Sahara' and Rudbeckia triloba. There are species and cultivars with single terminal inflorescences, and those with branched stems featuring multiple smaller flower heads. Flowers are in bloom in summer and fall. Harvest flowers that are mostly or completely open, the petals display full color and are fully expanded, and the stem is strong. Avoid cutting tight buds, as they will not open properly in the vase. Grab the middle of the stem and shake it gently; if the bloom stays firm and moves with the stem instead of flopping, it is ready. The stem should feel stiff all the way up to the base of the flower head. The best time of day to harvest cut flowers is in the morning, after dew has dried but before the heat of the day sets in. Using sharp, clean shears or snips, cut the stem at its base or just above a node (in the case of branching types). Strip the lower leaves from stems and then trop them into a bucket of cool water. Stems have a vase life of between

Rudbeckia flowers are also dried for use in crafts like resin art or fabric dyeing. When dried, they retain their rich petal color and dark centers. Make sure to harvest flowers that are fully open for drying. The flower heads should be flat. After harvesting, gather stems in small bunches and tie together with twine. Hang them upside-down in a dark, dry room with good ventilation and air flow. Individual flower heads can also be dried after their stems are removed, laid face-up in a single layer on a screen or tray. Whole stems can be used in dried rustic bouquets, and flower heads can be used in shadow boxes and resin art. Dried blossoms can be soaked for a day or two to extract an earthy golden-yellow to greenish dye for natural fibers.

Propagation

Rudbeckia, or Black Betty, can be propagated by division or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Black Betty, follow the instructions below:

Propagating Rudbeckia by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds in fall. The seed heads on Rudbeckia plants are pretty easy to spot, they're left behind after flowers have faded and are cone-shaped. Cut the flower head off of the plant and place it in a paper bag. Harvest as many flower heads as desired, and bring them indoors. Crush the seed heads to release the hundreds of tiny dark brown to black seeds stored inside.
Rudbeckia seeds will need a period of cold-stratification in order to germinate. To complete this process, first place seeds in a bag or other sealable container filled with moistened sand or peat moss. Then, place the container in the refrigerator (or similarly cool, dark space) for 2-3 months. The ideal temperature for cold-stratification is around 40 degrees Fahrenheit. After this period has passed, remove seeds from the container.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Rudbeckia by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.

As it dries, a Rudbeckia cone hardens and becomes tightly packed with hundreds of seeds.

Rudbeckia seeds are very small, brown to black, and slender to angular.

Problems and Pests

Certain Rudbeckia species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Rudbeckia plants can be susceptible to developing issues with the following pests and diseases in the landscape: