Illustration
Prairie Sun
Rudbeckia hirta 'Prairie Sun'
Prairie Sun blooms from July through September.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Prairie Sun
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 2.5 ft tall and 1.5 ft wide at maturity, in roughly 1 year (a house reading).
Pets
- Not yet checked for pets.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
No toxicity note is on file for Prairie Sun. That is not a clearance: check its safety for people and pets before planting.
What was checked
Nine facts were checked against named botanical sources, each recorded beside the sources that carried it: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. Soil, diseases, pests, toxicity and the plant's own names have not yet been read for this plant, and its trait tags are the ones a feature uses rather than every word a page prints. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Prairie Sun
Plant Prairie Sun in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 5, the middle of its hardy zones 3 to 8, spring means April to June and fall means August or September. Once settled, it blooms from July to September.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 5, the middle of this plant's hardy range, start with zone 5 in April. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Prairie Sun get?
2.5 fttall5 ft 7 inan adult1.5 ftwideSee Prairie Sun in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Prairie Sun
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Prairie Sun about 1.5 ft apart, center to center, so each plant has room to reach its full width.
Add Prairie Sun to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Prairie Sun's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 10 published sources on October 20, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Missouri Botanical Gardenheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- University of Minnesota Extensionheight, spread, sun, bloom months and color and trait tags
- University of Wisconsin HorticultureUniversity of Wisconsin-Madison Extensionheight, sun, water, bloom months and color and trait tags
- benary.comBenaryheight, spread, sun and bloom months and color
- Chicago Botanic Gardenhardiness zones, sun and bloom months and color
- fleuroselect.comFleuroselectheight, spread and bloom months and color
- cutflowers.ces.ncsu.eduNC State Extension, Cut Flower Cultivar Trialsbloom months and color
- sagebrushnursery.comSagebrush Nurseryheight and spread
- RHSRoyal Horticultural Societyheight
- University of Illinois Extensionheight
How the checking works, and what each standard covers, is on the verified plants page.
Where it grows wild
A garden form of Common Black-Eyed Susan (Rudbeckia hirta)
Its wild parent is native to 45 states and 3 provinces.
Its parent's own page: Common Black-Eyed Susan.
United States: Alabama, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming and 33 more
Canada: Manitoba, Ontario, Saskatchewan
Also grows wild, but is not native, in Alaska.
Range data from the World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 4.0, adapted) and USDA PLANTS. How the native range is credited.
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.