A southern red oak, or Quercus falcata, is a native of the southern United States and is closely related to the northern red oak, which is native to the northern United State. Commonly reaching more than 80 feet (24 m) tall, with a spread of more than 40 feet (12 m), the southern red oak has deep gray to brown bark that has many deep ridges and is very rough. The bark of this species is particularly tough, resisting the bark-stripping habits of rabbits and many deer species.
A deciduous species, meaning that it drops its leaves during late autumn and produces new leaves the following spring, the southern red oak is both versatile and tolerant. It thrives in dry areas, and even areas where the soil is nutrient-poor. The southern red oak is able to tolerate periods of drought, high temperatures and high humidity.
The tolerant and hardy nature of this species, combined with its large and complex root system, makes the southern red oak valuable to the environment. The complex root system makes the tree ideal for planting in exposed areas and areas of soil erosion. With this species being able to tolerate a wide range of conditions, it can be used to counteract soil erosion even in very dry or semi-arid regions and areas with very poor soil quality.
Aside from its environmental uses, the southern red oak is commonly used for flooring, fuel, interior fixtures and fittings, and construction materials. The southern red oak is listed as endangered in Pennsylvania and as threatened in Ohio — both northern states — even though it thrives in most of its native range. The southern red oak grows actively during the spring and summer but not during the colder months, even though this species can tolerate periods of temperatures as low as -13°Fahrenheit (-25°Celsius).
In some areas, hybrid or cross-breed varieties have developed. The original hybrid tree may have positive characteristics, often taking the best qualities of each parent variety. Hybrid southern red oak varieties either produce sterile seed that will not germinate or inferior, unstable seed. This is a second-generation hybrid and may germinate but will most likely produce stunted, weak trees that can be prone to disease and have other negative characteristics.