Illustration
Bur Oak
Quercus macrocarpa
Also called burr oak, moss-cap oak, mossycup oak and mossy cup oak
Bur Oak blooms from April through April.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Bur Oak
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 70 ft tall and 70 ft wide at maturity, in roughly 12 years (a house reading).
Is Bur Oak toxic to dogs?
- Listed as toxic to dogs by Royal Horticultural Society.
- Not yet checked for cats.
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 Bur Oak
Plant Bur Oak 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 in April.
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 Bur Oak get?
70 fttall5 ft 7 inan adult70 ftwideSee Bur Oak 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 Bur Oak
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Give Bur Oak about 70 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 Bur Oak 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
Bur Oak's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 12 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
- NC State Extensionheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- mckaynursery.comMcKay Nurseryheight, spread, hardiness zones, water and bloom months and color
- woodyplants.cals.cornell.eduCornell Universityheight, spread, hardiness zones, sun, water and trait tags
- The Morton Arboretumheight, spread, hardiness zones, sun and water
- Chicago Botanic Gardenhardiness zones, sun and bloom months and color
- University of Illinois Extensionheight, hardiness zones, sun and water
- RHSRoyal Horticultural Societyheight, sun and water
- Chicago Botanic Gardenbloom months and color
- Missouri Botanical Gardenbloom months and color
- NC State Extensionbloom months and color
- RHSRoyal Horticultural Societyheight
How the checking works, and what each standard covers, is on the verified plants page.
Where it grows wild
Native to 31 states and 6 provinces
United States: Alabama, Arkansas, Connecticut, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin, Wyoming and 19 more
Canada: Alberta, Manitoba, New Brunswick, Ontario, Quebec, Saskatchewan
Recorded growing wild in 1,026 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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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.