Red Oak – Quercus rubra

Red Oak – Quercus rubra
Family Fagaceae – Beech, Chinkapin and Oak

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Northern red oak has been extensively planted as an ornamental for brilliant fall foliage.
Red Oak spring foliage and catkins
There are about four hundred species in the oak genus (Quercus) worldwide. Oak trees are majestic beauties and symbols of strength in many cultures. The oak is the national tree of not only the United States, but of England and Germany as well.

Northern red oak (Quercus rubra), also known as common red oak, eastern red oak, mountain red oak, and gray oak, is widespread in the East and grows on a variety of soils and topography, often forming pure stands. Moderate to fast growing, this tree is one of the more important lumber species of red oak and is an easily transplanted, popular shade tree with good form and dense foliage.

Northern red oak is the only native oak extending northeast to Nova Scotia. It grows from Cape Breton Island, Nova Scotia, Prince Edward Island, New Brunswick, and the Gaspé Peninsula of Quebec, to Ontario, in Canada; from Minnesota South to eastern Nebraska and Oklahoma; east to Arkansas, southern Alabama, Georgia, and North Carolina. Outliers are found in Louisiana and Mississippi. [2]

Red Oak Habit
Red Oak at the Morton Arboretum is 69 years old

Numerous other tree species are associated with northern red oak include white ash (Fraxinus americana) and green ash (F. pennsylvanica); bigtooth aspen (Populus grandidentata) and quaking aspen (P. tremuloides); American elm (Ulmus americana)and slippery elm (U. rubra); pignut hickory (Carya glabra), bitternut hickory (C. cordiformis), mockernut hickory (C. tomentosa), and shagbark hickory (C. ovata); scarlet oak (Quercus coccinea), southern red oak (Q. falcata), post oak (Q. stellata), and chinkapin oak (Q. muehlenbergii); northern white-cedar (Thuja occidentalis); yellow buckeye (Aesculus octandra); cucumber magnolia (Magnolia acuminata); hackberry (Celtis occidentalis); butternut (Juglans cinerea); black walnut (J. nigra); blackgum (Nyssa sylvatica); and sweetgum (Liquidambar styraciflua). [2]
Acorn Weevil
Acorn Weevil, Curculio sp. [3]
The most destructive defoliating insect attacking northern red oak is the imported gypsy moth (Lymantria dispar). This insect repeatedly defoliates trees and has killed oaks including northern red oak in a wide area in the northeastern United States. Northern red oak can recover from a single defoliation but may be weakened enough for some disease or other insects to attack and kill them. Other defoliators, that attack northern red oak are the variable oakleaf caterpillar (Heterocampa manteo), the orangestriped oakworm (Anisota senatoria), and the browntail moth (Nygmia phaeorrhoea). The Asiatic oak weevil (Cyrtepistomus castaneus) attacks northern red oak seedlings and has the potential to seriously affect seedling growth because the larvae feed on the fine roots while the adults feed on the foliage.

Much damage is done to northern red oak acorns by the nut weevils (Curculio spp.), gall-forming cynipids (Callirhytis spp.), the filbertworm (Melissopus latiferreanus), and the acorn moth (Valentinia glandulella). In years of poor acorn production, these insects can destroy the entire crop [2].

Northern red oak is monoecious. The staminate flowers are borne in catkins that develop from leaf axils of the previous year and emerge before or at the same time as the current leaves in April or May. The pistillate flowers are solitary or occur in two- to many-flowered spikes that develop in the axils of the current year's leaves. The fruit is an acorn or nut that occurs singly or in clusters of from two to five, is partially enclosed by a scaly cup, and matures in 2 years. Northern red oak acorns are brown when mature and ripen from late August to late October, depending on geographic location.

Wildfires seriously damage northern red oak by killing the cambial tissue at the base of trees, thus creating an entry point for decay-causing fungi. Wildfires can be severe enough to top kill even pole- and sawtimber-size trees. Many of the top-killed trees sprout and thus create new evenaged stands, but the economic loss of the old stand may be great. Small northern red oak seedlings may be killed by prescribed fires, but larger stems will sprout and survive, even if their tops are killed.

Oak wilt (Ceratocystis fagacearum) is a potentially serious vascular disease of northern red oak and kills trees the same year they are infected. It usually kills individuals or small groups of trees in scattered locations throughout a stand but may affect areas up to several hectares in size. Oak wilt is spread from tree to tree through root grafts and over longer distances by sap-feeding beetles (Nitidulidae) and the small oak bark beetles (Pseudopityophthorus spp.).


  1. Red Oak, Morton Arboretum accession 656-40*1, photographed May 8, 2009. Photgrapher: Bruce Marlin
  2. Ivan L. Sander, USDA Forest Service Silvics Manual, Northern Red Oak
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Family Fagaceae – Beech, Chinkapin and Oak
Oak trees are a symbol of strength and stability; acorns are symbolic of enormous potential in a small package. Here are pictures and information on some of the oldest oaks and beeches on the planet. Find extensive descriptions and landscape planning information. Leaves, foliage, bark detailed in pictures. 
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