Quercus rubra (Red Oak)

Noted for its brilliant fall color, Quercus rubra (Red Oak) is a fast-growing, large deciduous tree adorned with an open, rounded to broad-spreading crown. The foliage of broad, lustrous dark green leaves, adorned with 7-11 toothed lobes, turns russet-red to bright red in the fall. Inconspicuous yellow-green catkins appear in spring as the leaves unfurl.

Emerging a dusty bronze-red color, the spring foliage creates an effect as beautiful as any spring-flowering tree. Reminiscent of ski trails, the branches, and upper trunk are marked with long, pale gray longitudinal lines.

Among the first of the landscape oaks to ripen, the acorns are a valuable source of food for small mammals and birds, but Red oak may take up to 40 years before the first crop of acorns is produced.

Handsome, stately, and adaptable, red oak is an excellent specimen tree for large areas, including urban areas. It is the state tree of New Jersey and a common symbol of strength and endurance in American culture.

Quercus rubra is native to eastern and central North America, including parts of the United States and Canada.

What Should I Grow Red Oak?

Red oak provides numerous benefits to the environment and the landscape. Some reasons why you should consider growing this native oak include:

Environmental benefits: It is a native tree species that supports a variety of wildlife and helps to maintain healthy ecosystems. It attracts game birds, game mammals, migrant birds, and small mammals.

Aesthetic appeal: It has a beautiful, distinctive appearance with its broad, rounded canopy and rich, reddish-brown bark.

Long lifespan: Red oak is a long-lived tree, with some specimens living for up to 500 years.

Shade and privacy: It provides ample shade and privacy, making it an ideal choice for large properties, parks, and public spaces.

Low maintenance: Once established, it is a relatively low-maintenance tree that requires little pruning or other upkeep.

Red Oak Growing Tips

Red oak can grow up to 50-70 feet tall and wide (15-21 m). Here are some general guidelines for growing this oak tree:

Sunlight: Red oak prefers full sun to partial shade to grow well, so choose a spot that receives at least six hours of direct sunlight per day.

Soil: It prefers fertile, acidic, sandy, loam, well-drained soils with a pH range of 5.0 to 6.5. However, it is adaptable and tolerates alkaline soil and clay soil.

Water: Red oak trees are generally tolerant of drought conditions once they are established, but young trees may need more frequent watering during dry spells. Make sure the soil is moist but not waterlogged.

Fertilizer: Red oak doesn’t typically require fertilizer, but if growth is slow or leaves are yellow, a slow-release fertilizer can be applied.

Pruning: Trees generally don’t require pruning unless there are dead, damaged, or diseased branches that need to be removed. Pruning should be done in late winter or early spring while the tree is still dormant. It’s important to make clean cuts and not to remove more than 25% of the tree’s crown in a single year. It’s also recommended to avoid pruning during the growing season, as this can make the tree more vulnerable to pests and diseases.

Mulch: Applying a layer of mulch around the base of the tree can help to retain moisture and suppress weeds.

Planting: Red oak can be planted in the spring or fall. Dig a hole that is at least two times the size of the tree’s root ball, and make sure the tree is planted at the same depth as it was in the nursery container.

By following these guidelines, you can successfully grow a healthy and beautiful tree.

Red Oak Propagation

Red oak trees can be propagated through either seed or cuttings. Propagation by seed is the easiest and most common method, but it can take a few years for the seedlings to reach a suitable size for transplanting.

Collect acorns from a mature tree in autumn after they have fallen to the ground.

Soak the acorns in a bucket of water for a day or two to remove any dirt or debris.

Discard any acorns that float, as they are likely to be infertile.

Place the remaining acorns in a plastic bag with some moist peat moss, and keep them in the refrigerator for several weeks to simulate winter.

After the cold stratification period, plant the acorns in pots filled with well-draining soil, and water them regularly.

Place the pots in a sunny location, and protect the seedlings from extreme heat or cold.

As the seedlings grow, gradually acclimate them to outdoor conditions by placing them outside for increasingly longer periods of time.

Transplant to their permanent location in the ground when seedlings reach 12-18 inches in height (30-45 cm).

Pests and Diseases

Red oak trees are susceptible to various pests and diseases that can cause significant damage to the tree’s health and appearance. Here are some of the common pests and diseases that can affect red oaks:

Caterpillars: Red oak trees are susceptible to a range of caterpillar pests, including the gypsy moth, tent caterpillar, and fall webworm. These caterpillars can cause defoliation of the tree, leading to stress and potentially death if the infestation is severe. To control caterpillars, it is important to monitor the tree for signs of infestation and take action early.

Galls: Red oak galls are abnormal growths on the twigs, leaves, and acorns of red oak trees. They are caused by insects that lay eggs in the oak tissue. While red oak galls can be unsightly, they generally do not cause significant harm to the tree unless they become very numerous.

Leaf blister: Red Oak Leaf Blister is a fungal disease that affects the leaves of red oak trees. It appears as small, raised, yellowish-green spots on the upper surface of the leaves, which then turn brown and develop into raised blisters. The disease does not usually cause severe damage to the tree, but repeated infections can weaken the tree over time.

Oak wilt: This serious fungal disease affects red oaks, causing the leaves to wilt and turn brown. The disease can kill the tree within a few weeks or months.

Powdery mildew: Powdery mildew is a common fungal disease that typically appears as a white or grayish powdery coating on the leaves, stems, and flowers of the tree. The disease can cause significant damage to the tree, including stunted growth, leaf drop, and reduced photosynthesis. It is important to maintain good tree health by providing adequate water, nutrients, and sunlight to prevent and control powdery mildew on red oak.

Scale insects: These pests can suck the sap from the tree, causing yellowing and wilting of the leaves. Insecticidal soaps and oils can be used to control small infestations, while severe cases may require the help of a professional arborist.

Toxicity: Red oak is not considered toxic to humans, although it is not typically consumed as food. However, the leaves and acorns of the tree can be toxic to some animals, such as horses and cattle, due to the presence of tannic acid. Ingestion of large amounts of acorns can cause digestive problems and possibly kidney damage in some animals.