Red oak

Sun

Full sun is best; young trees tolerate partial shade.

Water

Water deeply during dry spells for the first two or three growing seasons. Established trees tolerate moderate drought but grow best with reliable moisture.

Soil

Deep, well-drained, acidic to neutral soil. Tolerates loam, sand and well-drained clay; alkaline soil can cause yellow leaves, and prolonged waterlogging damages roots.

Height

60-80 ft (18-24 m)

Spread

45-60 ft (14-18 m)

Flowers

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

Foliage

Large green leaves with pointed, bristle-tipped lobes and relatively shallow sinuses. Autumn colour ranges from russet-brown to deep red; young trees may retain some brown leaves into winter.

Growth

Moderate to fast when young, often 1-2 ft (0.3-0.6 m) per year in suitable conditions.

Care needed

Low

• Plant with the root flare visible at soil level; choose a site large enough for the mature canopy.
• Water the root area deeply during dry weather while the tree establishes, rather than giving frequent light sprinklings.
• Spread a 2-3 in (5-8 cm) layer of organic mulch over the root area, keeping it clear of the trunk.
• Do not routinely fertilise; investigate soil pH and nutrient levels if growth is weak or leaves turn yellow.
• Stake only if the root ball is unstable, using flexible ties, and remove supports after establishment.
• Keep digging, soil compaction and lawn equipment away from the trunk and major roots.

Pruning. Prune young trees during winter dormancy to retain one main leader and remove damaged or poorly attached branches; avoid heavy crown reduction. Where oak wilt occurs, follow local guidance on safe pruning dates and use a qualified arborist for large branches.

Winter

Inspect branch structure and carry out light formative pruning during dormancy, following local oak-wilt guidance.

Spring

Plant container-grown trees while conditions are cool and the soil is workable; water thoroughly.

Late spring

Check new leaves for yellowing between green veins, which can indicate unsuitable alkaline soil.

Summer

Water young trees deeply during dry spells and check that ties are not rubbing or constricting the trunk.

Autumn

Collect fallen leaves for leaf mould, or leave a loose layer beneath the canopy where practical.

Late autumn

Plant dormant trees where the ground is workable; refresh mulch without piling it against the bark.

• Use as a specimen shade tree in a large lawn, allowing generous clearance from the house.
• Plant in spacious parkland groups for a broad canopy and autumn colour.
• Combine with smaller woodland trees and shade-tolerant groundcover along a woodland edge.
• Use in large eastern North American native gardens to support insects, birds and mammals.

Garden styles it suits: Grand estate, Woodland, Wildlife garden, Autumn colour, Traditional and New England.

Plant it with: Eastern redbud, Flowering dogwood, Witch hazel, Christmas fern, Wild ginger and Pennsylvania sedge.

Wildlife: In its native range, supports many moth and butterfly caterpillars, including those eaten by nesting birds. Acorns feed squirrels, jays, deer and other wildlife; older trees provide shelter and nesting sites.

• Oak wilt: a serious, often fatal disease in affected parts of North America. Avoid pruning during locally restricted periods, do not move infected firewood, and seek prompt professional diagnosis for sudden wilting.
• Iron chlorosis: leaves turn yellow between green veins on alkaline soils. Test the soil; specialist treatment may help temporarily, but a better-suited planting site is the lasting solution.
• Spongy moth caterpillars: heavy infestations can strip foliage. Monitor egg masses and caterpillars, protect young trees, and seek local advice before treating large trees.
• Bacterial leaf scorch: recurring brown leaf margins and gradual canopy decline can occur, especially in parts of North America. Maintain moisture during drought and obtain an arborist's diagnosis; there is no cure.

Acorns, buds and leaves contain tannins and can poison dogs, cats, horses and people if eaten in sufficient quantity. Large or repeated intake can cause digestive illness and serious kidney damage, particularly in grazing animals; fallen acorns also pose a choking or obstruction risk to pets. Keep horses away from accessible foliage and heavy acorn falls, and seek veterinary advice after substantial ingestion.

Where it spreads. Introduced populations spread aggressively in some European woodlands, including parts of Belgium, Germany and Poland, where the species is regarded as invasive. Check local guidance before planting near natural woodland outside its native North American range.

• Pin oak (Quercus palustris)

  Leaves have much deeper sinuses, often nearly reaching the midrib. Lower branches typically droop, and its acorns are smaller.

• Scarlet oak (Quercus coccinea)

  Leaves usually have deep, rounded sinuses and a glossier surface; its acorn cup encloses more of the nut than red oak's shallow, saucer-like cup.

• Black oak (Quercus velutina)

  Buds are conspicuously hairy, leaf undersides often retain hairs along veins, and the acorn cup is deeper with coarser scales.

Quercus is the Latin name for oak, and rubra means red, referring to the tree's reddish colouring.

Propagation. Grow from sound acorns collected in autumn. Keep them moist through a cold period, either by sowing outdoors in rodent-proof containers or by moist cold stratification in a refrigerator, then sow in deep pots. Do not let acorns dry out; transplant seedlings while young to limit root disturbance.

Accepted botanical name

Quercus rubra

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alabama, Arkansas, Connecticut, Delaware, District of Columbia, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky and Louisiana.

Measured

Soil pH 4.3 to 7.3. Average height 1865 cm.

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