How to Grow Black Eyed Susans

Rudbeckia has suffered from over exposure, yet there is a great deal of variety within the species and they are true workhorses, with very few problems. Most Rudbeckia come in shades of yellow or orange, with a dark center seed head, but there are also russet, bronze and mahogany tones. The flowers are daisy-like and can be single, semi-double and fully-double. You can tell them apart from coneflowers by their coarse-textured, hairy leaves. How to Grow Black Eyed Susans!

The most commonly thought of Rudbeckia is the Black-eyed Susan, a daisy-like flower with gold petals and a dark center seed head. The foliage on Rudbeckia is scratchy, hairy and not one of its best features. But the flower heads are quite varied among the species: Rudbeckia ‘Cordoba’ looks like a blanket flower. Rudbeckia ‘Maya’ resembles a tall marigold and Rudbeckia ‘Cherokee Sunset’ has an almost Chrysanthemum look.

Latin Name:

Rudbeckia

Common Name(s):

Black-eyed Susan, Brown-eyed Susan, Conedisk, Conedisk Sunflower, Gloriosa Daisy Tall Coneflower

USDA Hardiness Zones:

Hardiness will vary with species and not all Rudbeckia are perennial plants. Those that are generally are reliable in USDA Hardiness Zones 4 – 9.

Mature Size:

Plant size varies greatly, from dwarf (1 ft.) varieties like ‘Becky’ and ‘Toto’, to the giant Rudbeckia maxima, which can reach 9 ft.tall. Growing conditions and weather also affect the mature size of plants.

 Exposure:

You see the best flowering in full sun, but the plants can handle partial shade.

Bloom Period:

Rudbeckia plants start blooming in mid-summer and can repeat bloom into fall. Seed started perennials can bloom the first year if started early enough.

Design Tips:

Rudbeckia plants work equally well as a complement to blue and purple flowers, like Russian sage and Veronica or mixed in with other jewel tones, like Sedum ‘Autumn Joy’, Purple Coneflower and New England Asters.

Rudbeckia also make great cut flowers and even the seed heads will hold up in arrangements.

Suggested Varieties:

• Rudbeckia fulgida var. sullivantii ‘Goldsturm’ – The standard for Rudbeckia. Long blooming and virtually pest free. (2′)
• Rudbeckia hirta ‘Cherokee Sunset’ – Double and semi-double flowers in shades of yellow, orange, red, bronze and mahogany. Short lived, but re-seeds itself.(2′)
• Rudbeckia hirta ‘Indian Summer’ – Traditional daisy-like, large yellow flowers. Short lived, but re-seeds itself or grow as an annual. (3-4′)
• Rudbeckia ‘Toto Rustic‘ – A dwarf Rudbeckia in fall colors. There’re also golden ‘Toto’ & pale ‘Toto Lemon’.
• Rudbeckia maxima Giant Coneflower – 5″ flowers and 1-2′ leaves on an imposing plant ( 5′ -9”)

Growing Tips:

Rudbeckia are easy to establish, naturalize well, and require little maintenance other than deadheading.

Rudbeckia can be started indoors, from seed. Plant about 6-8 weeks before last expected frost. Perennial varieties will germinate best if the pots are kept in the refrigerator or similarly cold place for 4 weeks after seeding. Then move them back to a warm spot (70ºF-72ºF) until seeds actually germinate.

Rudbeckia can also be direct seeded in the garden once daytime temperatures remain around 60ºF.

Of course, plants can be purchased and transplanted. They are not particular about soil but do best in soil that is not too rich, with well-draining conditions.

Maintenance:

Keep plants well watered the first season, to get them established. Once established, the will be quite drought resistant.

Go easy on the fertilizer. Too much will result in weak stems and plants. A side dressing of compost should be all they’ll need.

Regular deadheading of the faded flowers will keep the plants in bloom longer. You can let the last flowers of the season remain on the plants to go to seed and feed the birds, but you will also get a good deal of self-seeding, which might not be a bad thing.

Division is only necessary if the clump gets too large for its space. Rudbeckias don’t generally die out in the center and don’t require frequent division.

Pests & Problems:

Rudbeckia are deer resistant once their leaves become coarse and hairy, but tender young growth may get nibbled.

Powdery mildew will affect the leaves in hot, humid conditions. Minimize this by planting in full sun and thinning the plants to allow for good air circulation.

Source: The Spruce