Bur oak

Sun

Full sun; young trees tolerate light shade but develop best in open conditions.

Water

Water regularly while establishing; established trees tolerate drought and occasional flooding, but not permanently waterlogged soil.

Soil

Deep soil with reasonable drainage; tolerates clay, loam, sandy soil and a wide pH range, including alkaline conditions.

Height

60-80 ft (18-24 m), occasionally taller

Spread

60-80 ft (18-24 m)

Flowers

Spring, as leaves emerge; inconspicuous yellow-green male catkins and tiny female flowers.

Foliage

Large, leathery green leaves with rounded lobes, usually deeply narrowed near the middle and broader toward the tip; yellow-brown to brown in autumn.

Growth

Slow to moderate; faster when young in deep soil with adequate moisture.

Care needed

Low

• Drought tolerant
• Cold hardy
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   8 ft (2.5 m)

2. After 1 year

   11 ft (3.4 m)

3. After 2 years

   14 ft (4.4 m)

4. After 3 years

   17 ft (5.3 m)

5. After 5 years

   23 ft (7.1 m)

About 20 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Native to

the US and Canada

Growth rate

Moderate

• Plant a small, nursery-grown tree with the root flare at soil level; large specimens can be difficult to establish.
• Water deeply during dry spells for the first two or three growing seasons, allowing the soil surface to dry between waterings.
• Maintain a broad mulch ring 2-3 in (5-8 cm) deep, keeping mulch away from the trunk.
• Do not fertilize routinely; use a soil test if growth or leaf colour suggests a deficiency.
• Stake only if the root ball moves in wind, and remove supports after the first growing season.
• Keep paving, digging and heavy vehicle traffic away from the future root zone.

Pruning. Prune young trees in winter to develop a strong central leader and well-spaced branches; leave major work on mature trees to a qualified arborist. Where oak wilt occurs, avoid pruning during the locally advised high-risk spring and summer period.

Winter

Inspect branch structure and carry out necessary formative pruning while dormant.

Early spring

Plant while dormant if the soil is workable and not waterlogged; refresh the mulch ring.

Late spring

Check leaf expansion and look for unusual wilting, spotting or branch dieback.

Summer

Water young trees deeply during dry spells and keep grass away from the trunk.

Autumn

Collect ripe acorns promptly if you want to raise seedlings; remove unwanted seedlings around the garden.

Late autumn

Plant dormant trees where winters are mild enough for root establishment, and check young trunks for animal damage.

• Use as a specimen tree in a large lawn, with room for its wide crown and low spreading limbs.
• Place on the sunny edge of a native meadow, paired with prairie grasses and wildflowers.
• Plant in a spacious parkland or estate setting for long-term shade and winter branch structure.
• Use in a mixed native woodland edge with smaller flowering trees and shade-tolerant groundcovers.

Garden styles it suits: Grand estate, Native meadow, Woodland, Wildlife garden, Midwest prairie and Traditional.

Plant it with: Little bluestem, Prairie dropseed, Wild geranium, Pennsylvania sedge, Eastern redbud and Serviceberry.

Wildlife: Acorns feed squirrels, deer, jays and other wildlife. Leaves support many moth and butterfly caterpillars in its native range, while mature trees provide nesting sites, shelter and eventually cavities.

• Oak wilt: sudden wilting or branch death needs prompt professional diagnosis. Avoid pruning during local high-risk periods and seek specialist advice on infected trees and nearby root connections.
• Bur oak blight: repeated late-season brown leaf patches and premature leaf loss can weaken susceptible trees. Have persistent symptoms diagnosed; severely affected trees may benefit from arborist-applied treatment.
• Leaf and twig galls: most are cosmetic and need no treatment. Have extensive twig dieback assessed rather than spraying routinely.
• Poor establishment: deep planting, compacted soil and inadequate watering can cause decline. Keep the root flare exposed, protect the root zone and water deeply rather than little and often.

Acorns, buds and leaves contain tannins and can poison horses, dogs, cats and people if eaten in sufficient quantity. Horses are particularly at risk where fallen acorns or young foliage are accessible; poisoning can cause severe digestive and kidney damage. Keep pets and livestock from eating them, and do not eat raw acorns.

• White oak (Quercus alba)

  White oak usually has more evenly distributed rounded leaf lobes and a shallow, unf ringed acorn cup; bur oak has a fringed cup and often a deeply narrowed leaf middle.

• Swamp white oak (Quercus bicolor)

  Swamp white oak has more shallowly lobed leaves with distinctly whitish undersides and acorns on long stalks; bur oak usually has deeply lobed leaves and much more conspicuously fringed cups.

• Overcup oak (Quercus lyrata)

  Overcup oak has a cup that nearly encloses the acorn but lacks bur oak's shaggy fringe; its leaves generally have more pointed-looking, though bristle-free, lobes.

Quercus is the Latin name for oak, macrocarpa means large-fruited, and bur oak refers to the burr-like fringe around the acorn cup.

Propagation. Sow fresh, sound acorns promptly in autumn, protected from rodents. They can begin rooting soon after falling and should not be allowed to dry out; use deep containers or a nursery bed and transplant while young.

Accepted botanical name

Quercus macrocarpa

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alabama, Alberta, Arkansas, Connecticut, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine and Manitoba.

Measured

Average height 1520 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.