Red Oak
Quercus rubra
Deciduous TreeAbout Red Oak
Red Oak is a fast-growing, large shade tree widely planted across eastern North America. It is valued for its strong timber, attractive fall color, and adaptability to urban conditions. As a member of the red oak group, its acorns take two years to mature and have a slightly bitter taste.
Quick Facts
How to Identify Red Oak
- Leaves with 7-11 pointed, bristle-tipped lobes with deep sinuses
- Dark gray to black bark with broad, flat-topped, ski-track-like ridges
- Round acorns with flat, saucer-shaped caps
- Brownish-red fall color
- Broad, rounded crown with stout branches
Care Guide
- Water deeply during dry periods, especially when young
- Prune in late winter; avoid pruning in spring to reduce oak wilt risk
- Do not over-mulch or bury the root flare
- Tolerant of urban pollution and compacted soils
- Fertilize young trees in spring with a slow-release formula
Known Issues (8)
Spongy Moth (formerly Gypsy Moth)
MODERATEAn invasive moth introduced to Massachusetts in 1869. Caterpillars defoliate hundreds of tree species, preferring oaks. Repeated defoliation weakens and can kill trees, especially when combined with drought stress.
Affecting 20 regions
Oak Wilt
CRITICALA lethal fungal disease that affects all oak species, with red oaks dying within weeks of infection. It spreads through root grafts between neighboring oaks and via sap-feeding beetles. White oaks are more resistant but not immune.
Affecting 18 regions
Sudden Oak Death
MODERATEA water mold disease that has killed millions of oaks and tanoaks along the Pacific coast since the mid-1990s. It also infects over 100 other plant species that can serve as carriers, including rhododendron and bay laurel.
Affecting 2 regions
Powdery Mildew
LOWA widespread group of fungal diseases that produce a distinctive white powdery coating on leaves and shoots. It affects hundreds of tree, shrub, and plant species. Unlike most fungi, it thrives in warm, dry conditions with high humidity.
Affecting 49 regions
Armillaria Root Rot
HIGHOne of the most widespread and destructive forest diseases in the world, caused by a complex of honey mushroom species. It attacks stressed trees through root contact and can persist in dead stumps for decades, infecting nearby healthy trees.
Affecting 36 regions
Fusiform Rust
HIGHThe most damaging disease of loblolly and slash pines in the southeastern US. It causes spindle-shaped galls on stems and branches that weaken trees and make them susceptible to wind breakage. Oaks serve as the alternate host.
Affecting 11 regions
Bacterial Leaf Scorch
HIGHA chronic bacterial disease that affects many shade tree species, particularly oaks, elms, sycamores, and maples. The bacterium is transmitted by xylem-feeding leafhoppers and spittlebugs and colonizes the water-conducting vessels, restricting water flow. Symptoms worsen each year as more of the canopy is affected. There is no cure.
Affecting 19 regions
Phytophthora Root Rot
HIGHA group of water-mold diseases that attack the roots and root collar of many tree species. Phytophthora thrives in wet, poorly drained soils. It destroys fine roots and can girdle the trunk at the soil line. Affected trees show a general decline that is often misdiagnosed as drought stress. Oaks, dogwoods, rhododendrons, and many other species are susceptible.
Affecting 31 regions