Black-Eyed Susan (Rudbeckia hirta)
Black-Eyed
Susans (Rudbeckias) are noted for their large, daisy-type
blooms with prominent dark centers. Flowers come in shades of
yellow, orange and mahogany and bloom in from summer until the
first frost in autumn. It's easy to see the family resemblance
with their tall cousins, the sunflower.
Plants grow from 2 to 3 feet tall and are suitable for massed planting, wildflower meadows or beds and borders. Many species of butterfly are attracted to Rudbeckia, and the effect is particularly striking in the wildflower meadow. They are also delightful, long lasting cut flowers. To prolong vase life, immerse cut stem ends in boiling water for about 30 seconds before adding to your floral arrangement. Hold the flower head to the side to keep it out of the steam.
Plants will thrive in most climates except the tropics. They need sun all day to prevent stunting and encourage flowering. In very windy areas they will need wind protection unless they are closely planted. Black-Eyed Susans will grow in most any type of soil as long as it is well-drained.
Seeds can
be sown outdoors in spring, summer or fall. They can also be
started indoors in early spring and moved outdoors when the
danger of frost has passed, but few people do this since they
are so easy to start right in the garden. Rudbeckias are one
of the easiest plants you can start from seeds. Even if you
haven't had great success growing flowers from seeds in the
past, you can save yourself a good bit of time and money, and
be sure of success with Rudbeckias. You might get a better germination
rate if you keep your seeds in the refrigerator for about 3
weeks before planting, but it's not necessary.
There are many types of Black-eyed susans, and you'll find annual,
biennial and perennial types readily available. Regardless of
which type you choose, they are all eager reeseeders and because
of this useful habit will come back year after year. Plants
with biennial habits tend to be showy one year and weak the
next.
Growing
Black-Eyed Susans in Beds and Borders
Once seedlings are an inch or two tall, thin them to about 12
inches apart. Pinch out the growing tips when they are about
a foot tall for bushier, sturdier plants. You'll want to keep
your plants moist until well established. Mature plants are
quite drought tolerant. Monthly applications of complete plant
food results in larger plants and flowers.
Growing
Black-Eyed Susans as Wildflowers
Black-Eyed Susans are often found growing wild along roadsides
and in meadows across North America. A meadow of Rudbeckias
is easy to start - simply broadcast the seeds over prepared
soil. If possible, roll or press the seeds into the soil.
Propagation: seeds
Light: full sun
Flower Color: orange, yellow, mahogony
Bloom Time: summer, autumn
Height: 2 - 3 feet
Width: 12-18 inches
Soil Requirements: perfers soil with some organic matter
Zones: all except tropical
Uses: Beds, Borders, Wildflowers, Cut Flowers
