The Southern live oak, Quercus virginiana, is the official state tree of Georgia and gets its name because it holds its leaves all winter, dropping them only as new spring leaves emerge. It is one of the most impressive of the native American trees and one of the longest-living trees on Earth. It is an important shade tree and can be found in many Southern parks.
Quercus virginiana is one of the broadest-spreading oaks. Matures trees can have a spread twice as wide as they are tall, reaching heights between 40 and 60 feet with a spread between 80 and 120 feet. They have stout trunks that measure between 3 and 6 feet wide and gracefully arching branches that curve toward the ground and then sweep upward again. Newer cultivars, such as the Q. virginiana "high rise oak," have been bred to be narrower and taller, with a pyramidal shape. They can grow to 80 feet in height with a 40-foot spread. Such massive trees have large root systems that can lift sidewalks and driveways. They produce both male and female flowers that are nondescript and narrow acorns in clusters.
The Southern live oak is a low-maintenance tree. It is not particular about soil type, but the soil should be acidic and a little moist. It is tolerant of air pollution, compacted soil, poor drainage, salt spray and salinity, making it a good choice for urban parks. It is drought-tolerant and can withstand hurricanes and some flooding. It prefers full sun but will tolerate partial shade. It prefers warm, humid climates and is most prevalent in the southeastern United States and the Gulf Coast states.
Trees should be properly pruned to maintain good structure. This should be done by a certified arborist every five years and is best done in winter or summer.
Although live oaks are considered pest- and disease-free, oak wilt is a problem in central Texas. It is a systemic fungus disease spread by insects, animals and man, and it enters the tree through wounds in the bark. Leaves turn bronze. There is no cure, and infected leaves must be destroyed. Avoid pruning in the spring, when the disease is most active.
The lifespan of Quercus virginiana can be measured in centuries. The oldest-known live oak is called the Seven Sisters Oak in Mandeville, Louisiana. It is estimated to be 1,500 years old and has a trunk that measures 38 ft. in circumference. The Angel Oak in Charleston, South Carolina, is estimated to be more than 1,400 years old.
Live oaks are an important food source for many animals, including the Florida scrub jay, the wild turkey, the yellow-bellied sap sucker, the black bear, the white tailed deer, and squirrels and chipmunks. Many air plants, such as Spanish moss, can be found in its branches. It is also an important nesting site for birds. The wood is hard and difficult to work with, but it is also strong. Historically, it was of vital importance in early American ship building. The USS Constitution---nicknamed "Old Ironsides" because its hull was so hard---was constructed from the wood of live oaks.