Illustration
Indian Summer
Rudbeckia hirta 'Indian Summer'
Indian Summer blooms from July through September.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Indian Summer
Plant it in full sun. It prefers low water. It is hardy in USDA zones 3–7. Expect it to reach about 3 ft tall and 1.5 ft wide at maturity, in roughly 2 years (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 Indian Summer. 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 Indian Summer
Plant Indian Summer 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 7, 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 Indian Summer get?
3 fttall5 ft 7 inan adult1.5 ftwideSee Indian Summer 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 Indian Summer
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Indian Summer about 1.5 ft apart, center to center, so each plant has room to reach its full width.
Add Indian Summer 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
Indian Summer's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 8 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 GardenPlant Finderheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- all-americaselections.orgAll-America Selectionsheight, spread, sun, water, bloom months and color and trait tags
- parksbrothers.comParks Brothers Farmheight, spread, sun, water, bloom months and color and trait tags
- Chicago Botanic Gardenhardiness zones, sun, water, bloom months and color and trait tags
- harrisseeds.comHarris Seedsheight, spread and bloom months and color
- Iowa State University Extensionand Outreachheight, bloom months and color and trait tags
- RHSRoyal Horticultural Societysun, water and bloom months and color
- NC State ExtensionGardener Plant Toolboxsun and trait tags
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.