Growing Black-Eyed Susan (Rudbeckia hirta) for a Glowing Fall Garden

There are many varieties of Rudbeckia. Black-Eyed Susan (Rudbeckia hirta) is an extremely popular heirloom variety. This perennial wildflower native to North America has bright yellow petals surrounding a dark brown domed center (a look similar to coneflowers). Black-eyed Susan blooms prolifically in the second year after planting. It also readily self-sows and attracts pollinators.

I’ve noticed that even though they die back in winter, Black-eyed Susans come back bigger and bolder the next year. By July, the rudbeckias will be attracting butterflies and goldfinches.

This perennial wildflower is perfect for growing from seed. With this helpful growing information and simple seed germination tips, you’ll enjoy bright Rudbeckia hirta flowers year after year.

Start Black-eyed Susan seeds indoors six to eight weeks before the last frost or sow directly outside in prepared soil. Light is required for germination; firmly press into the growing medium to allow good soil-to-seed contact. Transplant outdoors when seedlings reach 6”.

Another option is to start seeds in July or August. You won’t get many flowers the first year, but the next year, you’ll have a vigorous plant full of flowers. 

Winter sowing is another way to start your Black-eyed Susan seeds. This way, you will have seedlings ready for transplanting without the hardening-off phase.

There are several ways to sow Black-eyed Susan seeds. Indoor seed starting gives you control over water, light, and temperature. 

• Use a seed starting mix.

• Gently press seeds onto the moist growing medium.

• The planting depth for seeds is 1/16”

• Black-eyed Susan seeds require light for germination. So be careful not to bury them.

• Place grow lights 2 to 3 inches above the seeds.

• Mist the seeds with water.

• Use a humidity dome or cover to help keep moisture in and prevent the seeds from drying out.

• The optimal soil temperature for germination is 70ºF.

• Seeds should start sprouting in 1 to 3 weeks.

• Once the seeds sprout and start sending down roots, water the seedlings from the bottom to avoid damping off.

Once the seedlings are 6 inches high and have at least two true leaves, you can start the transplanting process.

• First, start by hardening off your seedlings. Even though these will eventually be hardy perennials, the tender seedlings can’t go straight from the protective indoor environment to the outdoor garden. Also, you want to be past all chance of frost, and the ground should be 70ºF.

• Start with just an hour on the first day when taking them outside. Place them in a sheltered spot where they won’t get too much wind or sun.

• Increase the amount of time outdoors each day. When the Rudbeckia seedlings are ready for outdoor life, transplant them in the evening. This gives them time to adjust before the hottest part of the day.

• Space Black-eyed Susan plants 12 to 18 inches apart.

Full sun will give you the most amount of Black-eyed Susan blooms. This sun-loving plant can also bloom in dappled shade. But too much shade will result in fewer flowers.

Black-eyed Susan plants can thrive in all kinds of soil. As heirloom wildflowers, they are used to the natural growing conditions of the prairie. Black-eyed Susans are the perfect flower to grow in clay soil.

Mature Black-eyed Susan plants are drought-resistant. However, when growing from seed or transplanting seedlings, keep the soil moist but not waterlogged. Once the plants have a vigorous root system, give them sufficient water without allowing the soil to stay soggy.

There’s no reason to add additional fertilizer to these low-maintenance flowers.

You don’t have to deadhead Black-eyed Susans. They are prolific bloomers when grown in full sun. But you can cut flowers to enjoy indoors. They are also excellent at self-sowing, so you can cut off flowers before they drop their seeds to prevent them from dropping.

As winter approaches, you can let the flower heads go to seed. This will give you more plants in the spring. It will also provide food for the goldfinches. Black-eyed Susans are very cold-tolerant and can survive below-freezing temperatures. Black-eyed Susans need vernalization. This is a cold period that tells them to establish strong roots. Adding a thick layer of mulch can help keep the roots from freezing and thawing over winter. Black-eyed Susan plants can be divided in early spring before they start growing or in the fall when they’ve finished blooming.

Purple coneflowers - Echinacea or Purple coneflowers have similar low-maintenance growing requirements as Black-eyed Susans and make a nice color contrast.

Sunflowers - There are a range of colorful sunflowers that will grow well and can be used in flower arrangements along with Black-eyed Susans.

Bee balm - Bergamot or Bee Balm is a natural companion flower to Black-eyed Susan. They both thrive in sunny prairie locations.

Wildflowers like Black-eyed Susans are naturally somewhat pest and disease-resistant.

Aphids will find their way into everything. Spray them off and use other natural methods to get rid of them.

If plants have consistently wet leaves, they can get powdery mildew. Space plants far enough apart to allow for good airflow and avoid overhead watering.

Deer and rabbits tend to leave Black-eyed Susans alone.