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How to Grow Black Eyed Susans, a Native Plant

Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.

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One of my favorite late season bloomers are perennial Black Eyed Susans. Their bright yellow flowers light up my flower beds as my purple coneflowers are fading. The goldfinches continue to visit, feasting on this new source of seeds.

What are Black Eyed Susans?

Black eyed susans are a native plant, originally growing in the Eastern and Central areas of North America. Since colonization, they have been introduced in and have naturalized in the western parts of North America. They are members of the sunflower family. Their Genus is Rudbeckia. The two most commonly grown species are Rudbeckia hirta which are annuals and Rudbeckia fulgida which are perennials that are hardy in zones 4 through 9.

Both annuals and perennials grow 1 to 3 feet with flowers that are 2 to 3 inches across. The leaves are stiff and hairy. The annuals bloom from June until frost. Bloomtime for the perennials is late summer into fall.

The semidouble flowers of Cherokee Sunset come in rust, orange, yellow and gold

The semidouble flowers of Cherokee Sunset come in rust, orange, yellow and gold

My Favorite Varieties of Black Eyed Susans

My favorite among the annuals is Rudbeckia hirta ‘Cherokee Sunset’ . It was an All America Selections Award Winner in 2002. The plants grow and bloom readily from seed. The colors of the semi-double flowers are superb: rust, orange, yellow and gold. I deadhead the flowers all summer and then in the fall allow them to go to seed. They freely reseed into my garden and come up again the following year. I have only ever purchased one package of seed because they have reliably reseeded every year since.

My favorite among the perennials is Rudbeckia fulgida var. sullivantii 'Goldsturm'. It won the prestigious Award of Garden Merit of the Royal Horticultural Society in 1993 as well as the Perennial Plant of the Year Award in 1999. I love it because it is reliably hardy, blooms profusely, and readily spreads without being invasive. Whenever I have a spot in my garden where other plants struggle, I just transplant a clump of Goldsturm into that spot. The following year, it is blooming and starting to fill in the space.

A small clump of Goldsturm will readily fill any area in your garden.

A small clump of Goldsturm will readily fill any area in your garden.

How to Grow Black Eyed Susans

Black eyed susans grow best in full sun but will tolerate partial shade. My experience is that they actually do better in partial shade than other sun plants that supposedly will grow in partial shade. Space your plants 18 inches apart in well-drained soil. Keep them watered. Try not to let them dry out. Like most native plants, they don’t need regular fertilizing. You can use a balanced fertilizer, such as 10-10-10, once in the spring if you like.

Deadhead the annual species to keep them blooming all summer. Remove spent flowers from the perennials to encourage the plants to continue to bloom into the fall. You can either cut the perennials down to the ground after frost or you can leave the plants over the winter so that the birds can snack on the seed heads. In the spring, cut down the dead plants so that the new growth will be able to grow unimpeded.

How to Divide Black Eyed Susans

Perennial black eyed susans should be divided every 3 to 5 years to keep the plants healthy. If left undivided, the plants become overcrowded which encourages disease and insect infestation.

To divide your plants, use a shovel to dig up the entire clump. Then, using your fingers, gently pry it apart into 3 or 4 pieces depending on how large the clump is. Discard any dead or diseased plants. Make sure that each division has both roots and leaves. Replant your new divisions 18 inches apart.

How to Grow Black Eyed Susans From Seed

Black Eyed susans are easy to grow from seed. The annuals and the perennials are handled a little differently.

Annual Seeds

You can direct sow the annual seed in your garden in the spring once the daytime temperatures are reliably 60⁰F or warmer. Sprinkle the seeds on top of the soil. Do not cover them. They need sunlight to germinate. Germination should occur in 7 to 21 days. Once they have their second set of leaves, thin them to 18 inches apart.

You can also start your annual seeds indoors. Start them two weeks before your last frost date. Sow the seeds on top of the soil. Do not cover them. They need sunlight to germinate. Germination should occur in 7 to 21 days. You can transplant your seedlings outdoors when the daytime temperatures are reliably 60⁰F. Space them 18 inches apart.

Perennial Seeds

Perennial seeds need a period of cold stratification. The easiest way to do this is to sow your seeds in fall. Sow them on top of the soil. Do not cover them. They need sunlight to germinate. The seeds will germinate in the spring when the soil warms.

You can also start your seeds indoors. Start them 6 to 8 weeks before your last frost date. Sow the seeds on the surface of the soil. Do not cover them. They need sunlight to germinate. Gently water. Cover the container with a plastic bag and put the whole thing in your refrigerator for 4 weeks. This mimics winter weather. Check the container periodically to make sure the soil remains moist. After 4 weeks, remove the container from your refrigerator and remove the plastic. Place the container under lights or on a sunny windowsill. Germination should occur in 7 to 21 days. You can transplant your seedlings into your garden when the soil warms. Space them 18 inches apart.

© 2019 Caren White

Comments

Caren White (author) on September 06, 2019:

Kaili, mine also were shorter than usual. Isn't it fun to birdwatch in the winter when hungry birds visit the seedheads?

Kaili Bisson from Canada on September 06, 2019:

Hi Caren,

Thanks for this, I love the color they add to the garden when other stuff is fading. Mine never grew very tall this year, for whatever reason. They are right beside coneflowers, which are almost hip-height, but the susans never got above a foot or so tall. I leave the heads on both over winter, so the birds can have a snack.

Caren White (author) on September 05, 2019:

Linda, what kind of soil do you have? They need well drained soil. You may have to add some compost or sand to it. I have a friend with the same problem and her soil is mainly clay.

Stephanie Bradberry from New Jersey on September 05, 2019:

I never used to be a fan of Black Eyed Susans. But they have come to grow on me over the years, especially when there is a lot of them in one area.

Linda Lum from Washington State, USA on September 05, 2019:

I see these all over the county. I know it's a sin to covet, but I covet my neighbor's black-eyed susans. I've tried, Lord knows I've tried. But I plant them (the perennial type) and they are great for a year, smaller the next, and never come back for a 3rd year. What or what could I be doing wrong?

Caren White (author) on September 05, 2019:

Jennifer, I'm a big fan of them too!

Jennifer Jorgenson on September 05, 2019:

I'm definitely gonna save this article. Black eyed susans are my FAVS!

Caren White (author) on September 05, 2019:

So glad you enjoyed them.

Heidi Thorne from Chicago Area on September 05, 2019:

These are so simple and beautiful! I don't have them in my yard, but some of our neighbors do.