Illustration
California Buckeye
Aesculus californica
Also comes in pink.
California Buckeye blooms from May through June.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing California Buckeye
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 7–8. Expect it to reach about 23 ft tall and 23 ft wide at maturity, in roughly 10 years (a house reading).
Is California Buckeye toxic to dogs or cats?
- Listed as toxic to dogs by NC State Extension and Royal Horticultural Society.
- Listed as toxic to cats by NC State Extension.
- Listed as poisonous to people by NC State Extension and Royal Horticultural Society.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
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 California Buckeye
Plant California Buckeye 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 7, the middle of its hardy zones 7 to 8, spring means March to May and fall means September or October. Once settled, it blooms from May to June.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 7, the middle of this plant's hardy range, start with zone 7 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does California Buckeye get?
23 fttall5 ft 7 inan adult23 ftwideSee California Buckeye 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 California Buckeye
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Give California Buckeye about 23 ft of clear ground in every direction, measured from its center. It is one plant with room around it, not a row, and a raised bed is too small for it.
Add California Buckeye 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
California Buckeye's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 8 published sources on November 5, 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
- calfloranursery.comCalifornia Flora Nurseryheight, spread, sun, water, bloom months and color and trait tags
- devilmountainnursery.comDevil Mountain Wholesale Nurseryheight, spread, hardiness zones, sun, water and bloom months and color
- NC State ExtensionGardener Plant Toolboxheight, spread, hardiness zones, sun, bloom months and color and trait tags
- Oregon State UniversityLandscape Plantsheight, hardiness zones, sun, water, bloom months and color and trait tags
- RHSRoyal Horticultural Societyheight, sun, water, bloom months and color and trait tags
- research.fs.usda.govUSDA Forest Service Fire Effects Information Systemheight, bloom months and color and trait tags
- botanic.cam.ac.ukCambridge University Botanic Gardenheight and bloom months and color
How the checking works, and what each standard covers, is on the verified plants page.
Where it grows wild
Native to 1 state
United States: California
Recorded growing wild in 43 counties.
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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Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.