Ornamental · Asteraceae
Black-eyed Susan
Rudbeckia hirta
Set it once in full sun, and this golden daisy returns to the border on its own each year.
Full sun
Every 7–10 days
USDA 3–8
2–4 ft · 0.6–1.2 m
Overview
Black-eyed Susan is the gold daisy that turns an ordinary stretch of border into something that reads like high summer itself, the same flower that warms roadsides and meadows across much of North America. A ring of yellow petals circles a dark brown center, and that quiet contrast is what makes it sit so easily beside grasses, gravel paths, and weathered timber. A member of the aster family, it grows fast and asks little, which is why it anchors so many relaxed, cottage-style plantings and casual cutting beds.
For all its presence, Rudbeckia hirta is short-lived, and that shapes how it works in a garden. Most plants behave as an annual, a biennial, or a brief perennial that bows out after a season or two. The seed it drops each fall keeps the look intact, so a single planting drifts and renews itself year on year, settling into a space the way a favorite armchair finds its corner.
Give it sun and decent drainage and it folds neatly into the rhythm of a low-fuss garden. It takes heat and the odd dry spell in stride once established, carries the display from early summer well into fall, and earns its keep into the cold months, the seed heads bringing birds to a window view when you leave the spent flowers standing.
Care
The short version: full sun and average, well-drained soil, with a deep drink every week or so while the plants settle into their spot. Feed it lightly, deadhead through summer to keep the border in flower, and let it self-seed so the look carries into next year.
Light
Black-eyed Susan gives its fullest show in full sun, six or more hours a day, which makes it a natural for an open, south-facing border. It will accept a touch of afternoon shade, but the more sun it draws, the more flowers it offers and the more upright the stems stand against a backdrop.
Water
Keep the soil evenly moist while the plants settle in, watering every 7 to 10 days when the weather runs dry. Once the roots reach deep, it carries a dry spell with ease. The single thing it will not abide is soggy, poorly drained ground.
Soil
Almost any well-drained soil suits it, clay, loam, or sand alike, so long as fertility stays modest. A pH from 6.0 to 7.5 covers the whole range it favors. Pass over the rich, heavy ground, since lean soil yields the better flowers for the display.
Humidity
Ordinary outdoor air is all it asks, so there is no figure to chase. Open air around the planting matters more than moisture, because crowded, still corners are exactly where powdery mildew creeps onto the leaves.
Feeding
This is a plant that performs best kept a little lean. Feed lightly, if at all, through the growing season, because too much nitrogen trades flowers for leaves. Modest soil and a sparing hand bring the bloom that carries a border.
Pruning
Deadhead the spent flowers through summer and the planting keeps offering fresh ones into fall. As blooming eases, cut the stems back for a tidy line, or leave the seed heads standing to feed the birds and lend the bed some winter structure.
Size & spacing
Plants rise 2 to 4 feet (60 to 120 cm) tall with a spread of 12 to 24 inches (30 to 60 cm). Allow each one that room so air moves through the planting and mildew finds less of a foothold.
When to plant
Black-eyed Susan keeps to the warm season. Start seed indoors in late winter or sow it straight into the bed once frost has passed, and the planting flowers from June through September, carrying the display into fall as long as you keep deadheading.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: About 6 to 8 weeks before last spring frost (around March 1 in the St. Louis area)
- Plant: After last spring frost, or direct sow at last frost date
- Harvest: June to September, extending into fall with deadheading
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
This is a forgiving plant, and most of what troubles it surfaces on the leaves or low on the stems where a glance picks it up. Catch it early and a quick response usually restores the look. Match what you see below, then act before it spreads through the planting.
Stems faltering and folding at the soil line
A sudden collapse signals southern blight, a soil fungus that arrives with warm, humid weather and can undo a planting quickly. Look to the base of the stem for white fungal threads and small tan pellets, the marks that confirm it. An infected plant is past saving, so lift it out with the soil around it, refine the drainage, and keep mulch drawn back from the stems going forward.
Fix:
- Remove and destroy infected plants and surrounding soil
- Improve drainage
- Avoid mulch piled against stems
Tattered holes marring the young leaves
Ragged gaps in fresh foliage usually trace back to slugs and snails, which favor the tender new growth and feast hardest through damp spells. A silvery slime trail near the damage is the telltale sign. Step out after dusk to gather them by hand, sweep away the litter they shelter beneath, and frame your seedlings with a barrier or trap until they outgrow the threat.
Fix:
- Hand-pick slugs and snails
- Reduce excess moisture and mulch near crowns
- Use barriers or traps around young plants
A pale, dusty veil settling over the foliage
That hazy film is powdery mildew, a fungus that drifts in late in the season when a planting grows crowded and the air goes still. It dulls the display more than it harms the plant, and it rarely proves fatal. Lift away the worst leaves, open up some breathing space between plants, and keep water at the base so the foliage stays dry and presentable.
Fix:
- Improve air circulation by spacing plants
- Remove and discard affected foliage
- Water at the base to keep leaves dry
Toxicity
Reassuring news for a home with animals: black-eyed Susan is not toxic. It never appears on the ASPCA's poison list, so pets, livestock, and children can share the garden with it in safety. The one thing to note is the bristly foliage, which can leave sensitive skin a little itchy, so keep gloves on hand when you cut it back.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
A cat that wanders the border and tastes a leaf has nothing to fear, since black-eyed Susan never appears on the ASPCA toxic list. The coarse, hairy foliage might bring on a brief moment of drooling, and that is the whole of it.
Dogs Safe
A dog can roam the planting and chew at it without harm. The bristly leaves may scratch a tender mouth, yet there is no toxin behind the display to cause concern.
Horses Safe
Horses can graze near a stand of Rudbeckia with no ill effect, as it carries no toxin known to trouble them.
Rabbits Safe
Rabbits can browse the foliage in safety, and the coarse texture, rather than any poison, is what tends to send most of them elsewhere.
Livestock Safe
Cattle, goats, and sheep can share a pasture with it untroubled, since nothing in the plant is poisonous to them.
Birds Safe
Come autumn the seed heads draw birds in, and the seeds make a welcome meal rather than a hazard. Left standing, the spent flowers carry finches through the leaner winter weeks.
People Safe
The plant is gentle to handle, though the stiff, hairy stems and leaves can leave sensitive skin a little itchy. A pair of gloves at cutting-back time settles the only real concern.
The bristly, hairy foliage and stems may cause mild skin irritation in sensitive individuals; wear gloves when handling.
Varieties
The Rudbeckia range runs wide, but a few selections stand apart for their scale, their coloring, or their staying power. These are the ones worth choosing by name.
Prairie Sun
A 2003 All-America Selections winner, this one offers large 5-inch blooms that wash from gold to lemon around an unexpected light green cone in place of the usual dark eye.
Indian Summer
Stout stems carry generous golden-yellow flowers that open a full 6 to 9 inches across.
Rudbeckia fulgida
The orange coneflower is the dependable perennial relation, spreading by rhizomes and holding through zones 3 to 9 where the short-lived R. hirta rarely settles for long.
How to propagate
Black-eyed Susan is among the easiest plants to multiply for a bigger drift, whether you raise it from seed or split an established perennial clump.
SeedEasy
Start indoors about 6 to 8 weeks before last frost, or direct sow at the last spring frost date · Blooms the first year from early spring sowing
Seed is the simplest route to a full display. Start it indoors 6 to 8 weeks before your last frost, or cast it straight across the bed once the frost has lifted, and an early spring sowing rewards you with flowers that same season. From there the planting tends itself, dropping seed each fall so fresh growth returns year after year.
DivisionEasy
Spring or fall for perennial clumps · Re-establishes within one growing season
Division suits the perennial kinds such as R. fulgida, since the short-lived R. hirta seldom forms a clump worth dividing. Lift and split an established clump in spring or fall to keep the stand fresh, and it settles back into the border within a single growing season.
Myths
Black-eyed Susan is a true long-lived perennial that comes back reliably for years.
In fact Rudbeckia hirta lives as an annual, biennial, or short-lived perennial. What returns each year is a new generation grown from dropped seed, not a long-lived root, as the parent plants scatter seed and fade while their offspring rise in their place. For a planting that comes back from the same crown season after season, choose R. fulgida instead.
Black-eyed Susan is poisonous to dogs and cats.
Rudbeckia appears nowhere on the ASPCA toxic plant database, and it is regarded as non-toxic to pets. The one footnote is the bristly foliage, which can leave sensitive skin mildly irritated.