Black-Eyed Susans are one of those flowers that can make a garden come alive in the middle of summer. Their bright golden-yellow petals and dark centers are easy to recognize, and once established, these tough plants can put on quite a show.
The good news is that Black-Eyed Susan care isn’t complicated. Give them enough sunshine, decent soil, and a little attention while they’re getting established, and they’ll reward you with weeks of beautiful flowers.
We’ve grown Black-Eyed Susans right alongside many of the flowering shrubs and perennials we love here at Bobby & Lynn’s Plant Farm. They’re especially impressive during the hottest part of summer, when some other plants are beginning to look tired.
Whether you’ve just planted your first Black-Eyed Susan or you’ve had them for years, here’s what you need to know.
What Is a Black-Eyed Susan?
Black-Eyed Susan is the common name used for several plants in the Rudbeckia genus. One of the best-known is Rudbeckia hirta, a North American native wildflower.
Depending on the species and variety, Black-Eyed Susans may behave as annuals, biennials, or perennials.
The classic flower is hard to miss. Golden-yellow petals surround a raised brown or nearly black center, creating the “black eye” that gives the plant its name.
They’re also valuable beyond their appearance. Their flowers attract pollinators during the growing season, while mature seed heads can provide food for birds.
For more botanical information about the plant, the NC State Extension Black-Eyed Susan plant profile provides an excellent overview of Rudbeckia hirta.
How Much Sun Do Black-Eyed Susans Need?
Sunlight is one of the most important parts of successful Black-Eyed Susan care.
For the best flowering, plant them where they’ll receive at least six hours of direct sunlight each day.
Full sun generally produces:
- More flowers
- Stronger stems
- Fuller plants
- Better overall growth
Black-Eyed Susans can tolerate some partial shade, particularly in hotter climates, but too much shade may cause plants to stretch toward the light and produce fewer flowers.
If your plants are healthy and green but aren’t blooming well, sunlight is one of the first things I’d check.
What Kind of Soil Do Black-Eyed Susans Like?
One reason Black-Eyed Susans are so useful in the landscape is that they aren’t terribly demanding about soil.
They’ll tolerate a range of conditions, but they perform best in soil that drains well.
Heavy soil that stays constantly wet can cause problems. Like many garden plants, Black-Eyed Susans don’t want their roots sitting in soggy ground for long periods.
If you’re planting in heavy clay, improving drainage and incorporating organic matter can help.
Don’t feel like you need extremely rich soil, either. Black-Eyed Susans are naturally tough plants and often perform beautifully without being pampered.
How Often Should You Water Black-Eyed Susans?
Newly planted Black-Eyed Susans need more attention than established plants.
During their first growing season, check the soil regularly and water deeply whenever it begins drying out. Deep watering encourages roots to move farther into the soil instead of remaining close to the surface.
Once established, many Black-Eyed Susans become fairly drought tolerant.
That doesn’t mean they never need water.
During prolonged periods of extreme heat and drought, supplemental watering can keep the plants healthier and flowering longer.
A good rule is to water deeply and less frequently rather than giving them a small splash every day.
Should You Deadhead Black-Eyed Susans?
You can—and there are some good reasons to do it.
Deadheading simply means removing flowers after they’ve faded.
Removing spent blooms keeps the plant looking cleaner and may encourage additional flowering, depending on the variety and where you are in the growing season.
But you don’t have to remove every old flower.
Later in the season, we like the idea of leaving at least some mature seed heads standing. Birds can feed on the seeds, and the plants may naturally reseed themselves.
So there’s nothing wrong with doing a little of both.
Deadhead earlier flowers when you want to keep the plant blooming and tidy, then allow some of the later flowers to mature naturally.
Do Black-Eyed Susans Spread?
They certainly can.
Depending on the type you’re growing, Black-Eyed Susans may spread through underground growth, seed production, or both.
That’s part of their charm.
A few plants can eventually develop into a beautiful patch of golden flowers.
But it’s also something to think about before deciding where to plant them.
If you want a very formal garden where every plant stays exactly where you put it, you may need to remove seedlings or divide plants periodically.
If you enjoy a more natural cottage-garden or meadow appearance, letting some Black-Eyed Susans spread can create a spectacular display.
Do Black-Eyed Susans Come Back Every Year?
This is where things can get confusing.
It depends on which Black-Eyed Susan you’re growing.
Some Rudbeckia species are true perennials and can return from their roots year after year in suitable climates.
Others, including some forms of Rudbeckia hirta, may behave as annuals, biennials, or short-lived perennials.
But even when an individual plant doesn’t live for many years, Black-Eyed Susans can reseed so successfully that it appears as though the same plants return every season.
That’s one reason it’s helpful to know the exact species or cultivar you’re buying.
When Do Black-Eyed Susans Bloom?
Black-Eyed Susans are best known for their summer and late-summer color.
Exact flowering time depends on the species, variety, climate, and growing conditions, but many begin blooming during summer and continue well into late summer or early fall.
That timing makes them particularly valuable.
By late summer, some spring-flowering plants have been finished for months. Black-Eyed Susans can step in and give the garden another burst of color.
They also pair beautifully with ornamental grasses, coneflowers, sedum, and many summer-flowering shrubs.
Should You Fertilize Black-Eyed Susans?
Usually, less is better.
Black-Eyed Susans generally don’t require heavy fertilization.
In reasonably healthy garden soil, they may need little or no supplemental fertilizer.
Too much nitrogen can actually work against you. You may end up growing plenty of lush green foliage without getting the flower production you wanted.
If your soil is extremely poor, adding compost or using a modest amount of balanced fertilizer may help.
But don’t assume more fertilizer means more flowers.
Why Isn’t My Black-Eyed Susan Blooming?
When a Black-Eyed Susan grows plenty of leaves but produces few flowers, look at its growing conditions before reaching for fertilizer.
Common reasons include:
- Not enough sunlight
- Excessive nitrogen
- Plants that are overcrowded
- Recent transplanting
- Extreme drought or heat stress
- Poor drainage
- The plant simply isn’t mature enough yet
Start with sunlight.
If the plant receives considerably less than six hours of direct sun, moving it to a sunnier location may make a big difference.
When Should You Divide Black-Eyed Susans?
Perennial Black-Eyed Susans can eventually become crowded.
If flowering begins declining or the clump has grown larger than you’d like, division can rejuvenate the plant while giving you additional plants for another part of the garden.
Spring and early fall are commonly good times for division, although your climate matters.
Gardeners in colder regions should allow enough time for fall divisions to establish roots before the ground freezes.
In very hot climates, avoid dividing during periods of extreme summer heat whenever possible.
Dig up the clump, separate it into smaller healthy sections, and replant them at approximately the same depth.
Then water thoroughly.
What Should You Do With Black-Eyed Susans in Fall?
You have options.
Some gardeners cut the plants back once flowering is finished.
Others leave them standing through fall and winter.
We’re fans of leaving at least some seed heads whenever practical.
The dried flower heads can provide seeds for birds, and standing stems add a little structure to an otherwise sleepy winter garden.
If you prefer a cleaner appearance, you can cut the plants back after they’ve gone dormant.
You can also leave them through winter and clean up the old growth before new growth begins in spring.
Are Black-Eyed Susans Good for Pollinators?
Yes, and this is one of the best reasons to grow them.
Their summer flowers can attract bees, butterflies, and other beneficial insects.
Later, once the flowers mature and produce seeds, birds may visit the dried seed heads.
Combining Black-Eyed Susans with other plants that bloom at different times can help create a garden that provides food for pollinators across a much longer season.
Can You Grow Black-Eyed Susans in Containers?
Yes.
Choose a container with drainage holes and use a quality potting mix rather than heavy garden soil.
Container-grown plants usually require more frequent watering than Black-Eyed Susans growing in the ground because pots can dry out quickly during hot weather.
The size of the container also matters.
A larger container holds moisture longer and provides more room for the roots.
If you’re growing a perennial variety in a container where winters are severe, remember that roots in pots experience colder temperatures than roots protected by the surrounding ground.
Are Black-Eyed Susans Deer Resistant?
You’ll often see Black-Eyed Susans described as deer resistant, but I wouldn’t call any flowering plant completely deer-proof.
Deer preferences vary tremendously from one location to another, and hungry deer sometimes eat plants they’re supposedly not interested in.
Black-Eyed Susans aren’t usually at the top of the menu, but don’t assume they’re completely safe if deer pressure is heavy where you live.
A Few Black-Eyed Susans Can Become Something Special
Black-Eyed Susans aren’t complicated plants, and that’s part of what makes them so enjoyable.
Give them sunshine. Help them establish a good root system. Don’t overfertilize them. Let some seed heads mature if you’d like them to reseed and provide food for birds.
Then stand back and enjoy them.
A small planting can eventually become a beautiful sweep of golden-yellow flowers buzzing with activity during the heart of summer.
And sometimes the plants that ask the least from us end up putting on one of the best shows in the garden.
Love growing flowering plants? Black-Eyed Susans are just one of the plants we grow and talk about here at Bobby & Lynn’s Plant Farm. If hydrangeas are part of your garden too, visit our Complete Hydrangea Care Guide for pruning, watering, blooming, winter care, and troubleshooting.
Have Black-Eyed Susans in your garden? We’d love to hear how they’re doing where you live. Tell us your state, province, or country and whether yours come back each year.
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