// SPECIES PROFILE · CANOPY TREE · NATIVE · TIMBER & WILDLIFE

Northern Red Oak

Quercus rubra

A fast-growing monarch of the eastern hardwood forest, Quercus rubra is distinguished by its deeply lobed leaves with bristle-tipped points, smooth gray bark on young trunks, and brilliant scarlet to russet-red fall color. Capable of 2 ft of growth per year — exceptionally fast for an oak — it produces large, relatively low-tannin acorns that are eagerly eaten by blue jays, wild turkeys, deer, and squirrels. In NE Oklahoma it reaches the southwestern edge of its range in the Ozark and Ouachita highlands, where it is confined to cooler, moister north- and east-facing slopes. It is second only to white oak in the commercial value of its timber among North American oaks.

// QUICK FACTS

Family: Fagaceae (beech/oak family)
Group: Large deciduous canopy tree
Native range: Eastern US reaching eastern OK in Ozark & Ouachita highlands
USDA hardiness: Zones 3–8 (Tulsa = 7a/7b)
Mature size: 60–90 ft tall × 40–60 ft wide
Growth rate: Fast — 2 ft/yr in youth; moderate with age
Sun: Full sun
Soil: Deep moist well-drained acidic soil; pH 4.5–6.5
Water: Moist well-drained; tolerates brief flooding; NOT for prolonged saturation
Bloom time: April–May (catkins, wind-pollinated)
Acorn: 3/4–1 in, shallow saucer-like cap, matures in 2 years
Fall color: Brilliant scarlet to russet-red
Wildlife value: 300+ insect spp · premier acorn for wildlife · cavity nesting
Lifespan: 150–300 years on good sites
Ecological role: Canopy dominant · keystone oak · timber species

Northern Red Oak (Quercus rubra) — deeply lobed leaves with bristle-tipped points and brilliant scarlet fall color — *Quercus rubra* — deeply lobed leaves with bristle-tipped lobes turning brilliant scarlet in autumn. Photo via Wikipedia / Wikimedia Commons.

Identification

[ field key — bark · leaf · acorn · red oak group ]

Habit & bark

A large deciduous tree with a straight, clear trunk and a rounded to broadly oval crown. In the open it develops a short trunk and wide-spreading branches; in the forest, a tall columnar trunk with a smaller crown. Bark on young trees and upper trunks is smooth and gray with a slight sheen, sometimes compared to a gray elephant's hide — a useful field mark when other oaks nearby have rougher bark. On older trunks, bark becomes dark gray-brown, furrowed into flat-topped ridges separated by shallow fissures. Bark is notably lighter and smoother than that of black oak (Q. velutina).

Leaves

Alternate, simple, 5–9 in long, 3–5 in wide, with 7–11 deep lobes that are coarsely toothed and bristle-tipped — the definitive character of the red oak group (Lobatae). Lobes are separated by deep, rounded sinuses extending more than halfway to the midrib. Upper surface is dark green, smooth, and glossy; lower surface is paler, smooth except for small tufts of hairs in the vein axils. Brilliant scarlet to russet-red fall color, among the best of the oaks. Leaves are held late into fall, often into November in Tulsa.

Flowers & acorns

Monoecious: male flowers in slender yellowish-green catkins 2–4 in long, female flowers inconspicuous in leaf axils, both appearing with the leaves in April–May. Acorns are large, 3/4–1 in long, ovoid to oblong, with a shallow saucer-like cap covering only the base (1/4 or less of the nut). The cap has tightly appressed, finely hairy scales. Acorns mature in two years (a red oak group trait) and drop in September–October. The nuts are less tannic (less bitter) than those of other red oaks and are preferentially consumed by wildlife.

Confusables

Black oak (Quercus velutina) has deeper acorn cups covering 1/2 the nut, and dark, deeply furrowed bark with yellow-orange inner bark. Shumard oak (Q. shumardii) is very similar but tolerates wetter, more alkaline sites; its acorn cup is slightly deeper and its range extends further south and west into Texas. Pin oak (Q. palustris) has smaller acorns, a strongly pyramidal form, and persistent lower dead branches. Scarlet oak (Q. coccinea) has deeper leaf sinuses and a top-shaped acorn cup. White oak (Q. alba) has rounded (not bristle-tipped) lobes and acorns maturing in one year.

Habitat & Range in NE Oklahoma

Quercus rubra is a tree of the eastern forest, and NE Oklahoma sits at the southwestern edge of its range. It is not found across most of the state but occurs in the Ozark and Ouachita highlands where elevation, aspect, and soil moisture create conditions cool and moist enough for this northern species to persist. In the Ozark region of NE Oklahoma (Delaware, Adair, Cherokee counties) it is found on moist, well-drained north- and east-facing slopes, in coves, and on benches — those microsites that stay cooler and retain more soil moisture through the Oklahoma summer.

It is absent from the drier Cross Timbers and from the heavy alkaline clay of the Tulsa basin in its native range. This is a critical point: northern red oak is not a tree for the average Tulsa yard unless you have deep, acidic, well-drained soil and are willing to irrigate during establishment. In its native microsites in the Ozarks, it grows in deep loamy soils derived from sandstone and chert, with a pH of 4.5–6.5, on protected slopes where the summer sun is moderated by aspect and elevation.

In cultivation, northern red oak is widely planted as a street and landscape tree across the eastern US, including in Tulsa, where it can succeed if given acidic soil amendments and consistent water through establishment. It is not adapted to the alkaline limestone-derived soils common in north Tulsa County without significant soil modification.

Ecology & Wildlife Value

[ keystone species · acorn ecology · insect community · cavity nesting ]

Keystone oak

Like all native oaks, Quercus rubra is a keystone species in eastern North American forests. It hosts 300+ insect species, primarily Lepidoptera (caterpillars of moths and butterflies) that feed songbird nestlings. The sheer biomass of insects produced by a mature red oak canopy is staggering — a single tree can support tens of thousands of caterpillars through the growing season, feeding entire food webs.

Acorn ecology

Northern red oak acorns are less tannic than those of other red oaks, which means wildlife preferentially consumes them. Documented acorn feeders include blue jays (which cache thousands of acorns and are the primary dispersal agent), wild turkeys, white-tailed deer, eastern gray squirrels, fox squirrels, chipmunks, raccoons, and black bears. Blue jays are particularly important: they select sound acorns, carry them long distances, and bury them individually in soil — essentially planting the next generation of red oaks.

Cavity nesting & structure

As trees mature past 80–100 years, they develop cavities and dead limbs that provide nesting and denning sites for woodpeckers (pileated, red-bellied, downy, hairy), wood ducks, screech owls, barred owls, flying squirrels, and raccoons. The large, spreading branches of open-grown trees also support bulky stick nests of hawks and herons where the tree grows near water.

Pests & diseases

Oak wilt (Bretziella fagacearum) is the most serious threat — a fatal fungal disease spread by sap-feeding beetles and root grafts. Armillaria root rot (Armillaria mellea) attacks stressed trees. Two-lined chestnut borer (Agrilus bilineatus) infests stressed and declining trees. Gypsy moth (Lymantria dispar) is a defoliator not yet established in Oklahoma but is a concern regionally. Bacterial leaf scorch (Xylella fastidiosa) causes marginal leaf browning and decline. Healthy, vigorously growing trees are the best defense against all of these.

Do not prune during the growing season. Pruning cuts between April and July attract sap-feeding beetles that can vector oak wilt. Prune northern red oak only during full dormancy (November–February) and paint all cuts larger than 2 in with pruning sealant immediately. This is the single most important cultural practice for preventing oak wilt in landscape trees.

Horticulture & Care

[ siting · planting · pruning · oak wilt prevention ]

When to plant

Transplant only as young container-grown or balled-and-burlapped trees in fall (October–November) or early spring (March–April). Fall planting is preferred because it allows root growth through the winter before summer heat arrives. Red oak develops a deep taproot early; older or root-bound nursery stock should be avoided — choose trees under 6 ft for best transplant success.

Planting & establishment

Sun: full sun. This is a canopy tree that will eventually dominate the site; do not plant under overhead wires or within 15 ft of structures.
Soil: deep, moist, well-drained acidic soil (pH 4.5–6.5). NOT for alkaline clay — iron chlorosis will develop in high-pH soils. If your soil is alkaline, choose Shumard oak instead.
Hole: twice the width of the root ball, same depth; slightly proud in heavy clay. Do not amend the backfill heavily — the tree must grow into the native soil.
Spacing: minimum 30–40 ft from other large trees, 20–25 ft from buildings, 10–15 ft from pavement.
Water: deep weekly soaking through the first three summers. Regular water during establishment is critical — this is not a drought-hardy species in youth.
Mulch: 3–4 in of shredded hardwood, extending to the drip line or at minimum a 6 ft diameter ring. Keep mulch 4 in away from the trunk flare.
Staking: only if necessary; remove after one year. Oaks develop stronger trunks when allowed to flex in the wind.

Pruning

Prune ONLY during full dormancy (November–February). Growing-season pruning attracts oak wilt vectors.
Paint all cuts larger than 2 in with pruning sealant or latex paint immediately after cutting — do not wait, do not skip this step.
Establish a central leader in young trees; remove co-dominant stems and branches with narrow crotch angles early.
Limb up gradually as the tree matures; never remove more than 25% of the live crown in a single pruning event.
Remove dead, diseased, or crossing branches anytime — dead wood does not attract oak wilt vectors.

Fertilization & long-term care

Fertilize sparingly if at all. A soil test is recommended before planting. In acidic sandy soils, young trees may benefit from a slow-release balanced fertilizer in early spring for the first 3–5 years. Mature trees in good soil need no supplemental fertilization. Avoid high-nitrogen fertilizers that push soft growth susceptible to borers and disease. Maintain the mulch ring as a permanent feature — it suppresses competition, retains moisture, and protects the trunk from mower damage.

Cultural & Material Uses

Northern red oak is one of the most commercially and culturally significant hardwood trees of eastern North America. Its combination of rapid growth, high-quality wood, and abundant wildlife value has made it a tree of exceptional utility.

Timber: premium hardwood — flooring, furniture, cabinets, millwork, veneer, interior trim, caskets, and pallets. The wood is strong, hard, heavy, and machines well with a characteristic open grain. It is second only to white oak in commercial value among North American oaks. The heartwood is pinkish-red-brown; the sapwood is pale.
Acorns as food: northern red oak acorns are less tannic than those of most other red oaks and were used by Indigenous peoples as a food source after leaching (boiling or soaking in running water to remove tannins). The leached acorn meal was used for bread, porridge, and soup thickener.
Ornamental: widely planted as a specimen shade tree for its rapid growth, symmetrical form, and brilliant scarlet fall color. Cultivars selected for fall color include 'Splendens' and 'Aurea' (yellow fall color).
Tanning: the bark is rich in tannins and was historically used for tanning leather, though less so than that of chestnut oak or eastern hemlock.
Medicinal: oak bark decoctions were used in folk medicine as an astringent, antiseptic wash for wounds and sore throats; these uses are historical and not recommended without professional guidance.
Urban forestry: one of the best oaks for urban planting where soil conditions are appropriate (acidic, well-drained), due to its tolerance of moderate soil compaction and its relatively fast establishment compared to white oak.

Sources & Further Reading

USDA NRCS PLANTS Database — Quercus rubra: plants.usda.gov/plant-profile/QURU
USDA Forest Service Silvics of North America — Quercus rubra, hardwood volume.
Lady Bird Johnson Wildflower Center — Quercus rubra: wildflower.org — QURU
Dirr, M.A. (2009), Manual of Woody Landscape Plants, 6th ed., Stipes Publishing — the standard ornamental reference for Quercus.
Sander, I.L. (1990), "Quercus rubra", in Burns & Honkala, Silvics of North America, Vol. 2: Hardwoods, USDA Forest Service Agriculture Handbook 654.
Tallamy, D.W. (2021), The Nature of Oaks, Timber Press.
Oklahoma State University Extension — HLA-6412 Selecting Trees for Oklahoma Landscapes.
Wikipedia — Quercus rubra: en.wikipedia.org/wiki/Quercus_rubra (CC BY-SA 4.0).

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In Ozark mesic forest plantings, northern red oak pairs naturally with: sugar maple (Acer saccharum), sassafras (Sassafras albidum), black tupelo (Nyssa sylvatica), American hornbeam (Carpinus caroliniana), spicebush (Lindera benzoin), and pawpaw (Asimina triloba).

Site northern red oak as the canopy dominant in a forest planting on deep, acidic, well-drained soil with protection from hot afternoon sun during establishment.