How to Grow Black-eyed Susans: The Complete Black-eyed Susan Flower Guide

Black-eyed Susans (Rudbeckia hirta)in a field

Black-eyed Susans (Rudbeckia)

Photo Credit
Flower_Garden/Shutterstock
Botanical Name
Rudbeckia hirta and other species
Plant Type
Flower
Sun Exposure
Full Sun
Part Sun
Bloom Time
Summer
Fall
Flower Color
Orange
Red
Yellow
Hardiness Zone
3
4
5
6
7
8
9
Special Features
Attracts Butterflies

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Planting, Growing, and Caring for Black-eyed Susans

Catherine Boeckmann

Beloved by pollinators, black-eyed Susans (Rudbeckia hirta) generally bloom from June to August, often blanketing open fields with their golden-yellow beauty. Learn how to care for this native wildflower, when to cut it back, and how to save seeds for replanting.

What Are Black-eyed Susans?

The “black eye” of black-eyed Susans refers to the dark brown center of its daisy-like flower head. A member of the aster family, Asteraceae, and native to eastern North America, it has become naturalized in Zones 3 to 9. And while some species of black-eyed Susans have additional names—such as Gloriosa daisies—they all belong to the Rudbeckia genus.

Black-eyed Susans grow 1 to 3 feet tall or more with leaves of 6 inches, stalks over 8 inches long, and flowers with a diameter of 2 to 3 inches. Butterflies, bees, and other insects are attracted to the flowers for the nectar. As they drink the nectar, they move pollen from one plant to another, causing it to grow seeds that can move about easily with the wind. Learn more about our favorite wildflowers.

“The Silvery Checkerspot butterfly uses Rudbeckia species as a host plant,” explains the “Seed is consumed by song birds, especially goldfinches.”

In the garden, they do well in landscapes, borders, butterfly gardens, or containers. Also, they are outstanding cut flowers.

Black-eyed susans are Sun worshipers who forgive neglect and are tough as nails. However, avoid overcrowding these plants or watering their leaves (vs. soil level), which can lead to fungal disease.

Note that varieties can be annual, biennial, or perennial. The popular Rudbeckia hirta is treated as a short-lived perennial. See more about the recommended varieties below.

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Planting

The black-eyed Susan thrives in full sunshine. It tolerates partial sun, but it will not bloom as reliably. It’s best if the soil is fertile (not poor), though this plant can tolerate tough conditions.

When to Plant Black-eyed Susan

  • Set new plants out in the spring after all danger has passed or plant in the fall. The optimal soil temperature for germination is 70° to 75° F. Do not plant in the hot summer.
  • If planting by seed, sow seeds about 6 weeks before the average last frost.

How to Plant Black-eyed Susan

  • Plants should be set 18 inches apart. Remove weeds and loosen the soil. Make a hole a few inches wider than the plant and set it in the hole; backfill it with soil, tamp gently, and water it well.
  • If planting from seed indoors, sprinkle seeds on top of the regular seed starting mix. Do not cover the seed, as they need light to germinate. Plant your seedlings outdoors after any danger of frost has passed. Since black-eyed Susans can spread between 12 to 18 inches, plant seeds closer to prevent lots of spreading, or plant further apart to make a nice border and to prevent the spread of disease.
  • Black-eyed Susan spreads by self-seeding (after the first year) and underground rhizomes; this can result in it overtaking other nearby flowers.

Growing

  • Check plants regularly to see if they need watering. Avoid letting them dry out, and avoid excess moisture on the leaves, as this can encourage disease. (Provide plants with proper spacing.)
  • Deadhead the flowers any time of year (remove the faded/dead flowers) to prolong blooming and minimize self-seeding.
  • Remove dead plant material in the spring to reduce the risk of infection.
  • Divide perennial types every 3 to 4 years to ensure healthy plants and prevent excessive spreading.

Should You Cut Back Black-Eyed Susans

When it comes to black-eyed susans, we prefer to delay cutting back until spring. 

  • This plant is a favorite with wildlife, native insects, and birds with its dried seeds. 
  • In addition, overwintering birds find protection in plant stubs and ground covers.
  • Plus, the mound of foliage will insulate the roots and protect the plant over winter. 

However, black-eyed Susans are a big reseeder. To avoid this, cut the spent flowers back just below the mound of foliage.

Types

As well as the traditional black-eyed Susans, which grow 1 to 3 feet tall (or more), there are dwarf varieties that reach no more than 1 foot (perfect for containers). Varieties can be annual, biennial, or perennial.

The popular roadside Rudbeckia hirta with showy yellow flowers is a biennial in the wild but treated as a short-lived perennial in the garden. It self-seeds abundantly, naturalizing easily. If you sow seeds 6 weeks before the last frost date, you’ll see flowers in the first year, and they may return a few more seasons (but you can’t always count on it). Some of its many hybrids include:

  • ‘Autumn Colors’: yellow, orange, red, and brown flowers; 18- to 24-inch stems
  • ‘Becky Mixed’: lemon-yellow, golden-yellow, dark red, and reddish-brown flowers; 10- to 16-inch stems
  • ‘Prairie Sun’: All-America Selections winner; 4- to 6-inch bright orange flowers that fade to yellow at the tips; 28- to 23-inch stems. !
  • ‘SDzԴǰ’: large golden flowers with big, chocolate-brown centers; 12- to 16-inch stems
  • ‘Toto Gold’: dwarf type; classic yellow flowers with black centers; 12- to 16-inch stems; ideal for containers

There are also true, long-lasting perennials that will keep coming back and blooming year after year.

  • ‘GDZٳܰ’ black-eyed Susans (Rudbeckia fulgida ‘Goldstrum’), known for its longevity and a regular plant in late summer and fall gardens
  • ‘Sɱ’ black-eyed Susans (Rudbeckia subtomentosa), bearing taller flowers and ideal for more naturalized garden or meadow
  • ’Gloriosa Daisies’ (Rudbeckia hirta ‘Gloriosa’), 12- to 36-inches tall and tolerates partial shade; giant, bi-color double flowers.

Finally, some Rudbeckia varieties are annuals, such as the Clasping Sunflower (Rudbeckia amplexicaulis), a low-growing plant for the front of a border garden.

Harvesting

Cut flowers for display just before buds completely open. Use large blooms as centerpieces and smaller ones as accents. Change the water every day to keep them fresh. Vase life is 8 to 10 days.

How to Collect Seeds of a Black-eyed Susan

Once the seed heads are dry and brown, it’s time to clip some stems. Pop off the seed heads from the stems and toss them in a small jar; close the lid and shake it to loosen the seedheads. Then, dump the seed heads from the jar into a sieve with a white piece of paper below it. Break up the seed heads in the sieve with your fingers. The seeds will come off and fall through the sieve onto the paper! Fold the paper in half and carefully funnel those seeds into a paper envelope. Close and label the envelope and store it in a cool, dry place. 

Learn more about how to save seeds for next year.

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Wit and Wisdom

  • Black-eyed Susans are meant to symbolize justice. Find out more flower meanings here.
  • The genus name Rudbeckia honors Swedish scientists Olaus Rudbeck (1630–1702) and his son, Olof Rudbeck (1660–1740).
  • The species name hirta means “hairy” and refers to the short bristles that cover the leaves.
  • Black-eyed Susans are the state flower of Maryland.

Pests/Diseases

Black-eyed Susans are deer-resistant plants.
Diseases: powdery mildew, aster yellows, Botrytis blight, southern blight, angular leaf spot, fungal leaf spot, downy mildew, rust, white smut, Verticillium wilt.
Pests: aphids, nematodes, slugs, and snails

Flowers
About The Author

Catherine Boeckmann

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s found each other. She leads digital content for the website, and is also a certified master gardener in the state of Indiana. Read More from Catherine Boeckmann
 

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Comments

Several people have written (below) of this problem. Before you can do anything you need to know what the problem is; here is our advice from below. See also the info under “Pests” above:

• There are also foliage-loving bugs. Go out after dark with a flashlight and examine your plant for slugs, earwigs, whiteflies, etc. (Google for photos or see our pest library). Once you identify the pest, you can figure out a control to deter it.

• One possibility is that your soil has become depleted … trying enriching it, but not too much. If they are super cramped, they may need to be divided. Another possibility is that surrounding plants or structures may have changed since last year and your ladies are getting less sun.

• Go out after dark with a flashlight and examine your plant for slugs, earwigs, whiteflies, etc. (Google for photos or see our pest library). Once you identify the pest, you can figure out a control to deter it.

• If this happened overnight, it would normally be a deer or rabbit or animal. They usually leave the stem and go for the leaves.
Otherwise, look carefully at the leaves. Caterpillars tend to chew holes in the leaves. Slugs chews ragged, irregular shaped holes in leaves that cross the veins. See our pests and critter library to I.D. and learn more: http://www.almanac.com/topics/gardening/pests-and-problems

We hope this helps!

 

 

Sherry Blanton (not verified)

8 years 6 months ago

My husband bought me a beautiful BES plant from the florist last July. I planted in the ground and it did well for the rest of the summer. I plucked off some dead heads that went to seed and sprinkled them down in the excess dirt around the plant. It is now the middle of May, and nothing is coming up. All of my other perennials are up, even the mums are coming up. Should i just consider it dead or wait a little while longer before planting something else in it's place?

Maury (not verified)

8 years 6 months ago

My black eyed Susans are growing quickly ( 12-18 inches now) and crowding out my Sweet Williams. Can I cut them back some to keep the other flowers from being smothered, or will that keep the BAS from blooming? I can just pull them up, but I think I need them for after the Sweet Williams stop blooming. If I do trim the back how tall should I leave them? If I cut them almost to the ground will they start over?? Thanks!

You can cut the flowers back to about 12 inches and the plant will get bushier and not grow as tall. You may loose some blossoms but the plant should bloom a little later in the summer.

Jo (not verified)

8 years 6 months ago

I am in zone 5, and late last Jul or August I planted several rudbeckia hirta (I think Denver Daisy but I can't remember for sure; the petals were burgundy toward the centers). It seemed to establish well and was still getting blooms well into October. I left it alone - didn't dead head anything or cut it back - until late December, when I did cut it to about 3 inches. I thought it was hardy and a self-seeder, and expected to see it back. It is now mid-May and there is no evidence of any rudbeckia. I planted it with double scoop coneflowers, all of which are coming up nicely. Is it too early still, or should I assume I lost it all? There is quite a bit of mulch down in the area, so maybe it wasn't able to seed well. I don't want to pull them and plant something else there if there is a chance it will still come up, but the empty spot needs filled with something. Thanks!

Our sources suggest that this plant is usually grown as an annual but the native form can occur as a biennial—this info from the Wildflower Org: http://www.wildflower.org/plants/result.php?id_plant=RUHI2

Other sources concur on the annual side; go ahead and plant something else.

Lisa (not verified)

8 years 6 months ago

I love Black eyed Susies~~ I'm trying to find the exact name of the ones where the flower heads are smaller than usual and they are taller than the typical BES's. Thanking you in advance. Lisa

Brenda (not verified)

8 years 8 months ago

It is March, and my BESs are black balls atop dead-looking stalks.We had very little snow this year in the Hudson Valley in NY. Do I cut them back, or are they dead? They come back every year, and I've never touched them. Should I pull out the old stalks?

Thank you for your help,
brenda

Sure, you can cut off the stalks. The new growth will come from the soil (root), not last year’s stem.

Deb Moe (not verified)

9 years 2 months ago

When it says to "cut back" the BES after flowering, what exactly does that mean? How far back do you cut them? We had an especially dry and hot summer, so they may have dried out, though I tried my best to keep them wet.