I think Live Oaks are the best trees in the world. They are arching, spreading, majestic, textured, and sculptural- all of the qualities that make large trees magical. They are evergreen oaks, meaning that their canopy is always full and green. The Live Oak graces the streets and parks of Houston in abundance because they are drought tolerant once established and a tough native plant for urban conditions. Did you know that there are dozens of other oaks native to our area? The Oak genus, Quercus, (pronounced kwerk-es) contains 600 species of trees and shrubs, and over 50 of them are native to Eastern North America. In fact, Texas is home to the most diverse set of native oaks in the United States. The theory is that all of the native oaks in North America can be traced to central Mexican origins. The native ranges of specific oak species is fascinating. Some, like the Bur Oak- Quercus macrocarpa, have a large native range throughout the midwest that stretches into the gulf coast Texas area. Others, like Myrtle Oak- Quercus myrtifolia, are located only in isolated areas of Florida and Georgia. With overlapping ranges and species with similar leaves, bark, and acorns, it can be tricky to distinguish between different species. I've attempted to remove some of the mystery by describing the distinctive features of oak trees found in Houston. This is not a complete list. Instead, it's a list of species that are perfect for Houston because they tolerate the "gumbo" soil and thrive in our humid hot weather. These trees are uniquely adapted to do well here and you should use them in your garden.
Swamp Chestnut Oak, Q. michauxii
Height: to 80 feet
Leaves: Obovate with wavy edges and 10-14 rounded teeth on each side.
Distinctions: grey-green underside of the leaves, leaves similar to chestnut (hence the common name)
Ecology: Native range throughout southeast. Likes moist soils and floodplains.
Bur Oak, Q. marcrocarpa
Height: to 80 feet
Leaves: Deeply divided lobes on lower half of leaves with broad rounded tip
Distinctions: Thick, knobby bark and twisted branches. Acorns are humongous! (hence the name MACROcarpa, meaning large seed)
Ecology: Great midwestern shade tree with a range throughout the Great Lakes and central plains region. Deciduous even in Houston. Native range in dry uplands.
Overcup Oak, Q. lyrata
Height: to 80 feet
Leaves: Narrow, oblong with 7-11 rounded or pointed lobes.
Distinctions: Long leaves, 5-8"
Ecology: Native range on wet clays and silty clay soils, especially waterlogged flood plains and swampy areas. Can occur in pure stands.
Lacey Oak, Q. glaucoides. syn. Q. Laceyi
Height: 35 feet
Leaves: Oblong elliptical, thick and leathery
Distinctions: Blue-gray leaf color, visible at a distance
Ecology: Native range in Texas hill country, Edwards Plateau, and isolated NE mexico at Higher elevations. Rocky limestone bluffs, occurring with junipers and mesquite.
Schumard Oak, Q. shumardii
Height: to 150'
Leaves: Elliptical, deeply divided with large rounded sinuses between lobes
Distinctions: Buttressed base of trunk with a shallow root system
Ecology:Native range in well-drained floodplains, throughout the southeast united states
Nutall Oak, Q. nuttallii
Height: to 100'
Leaves: Elliptical and deeply divided into 5-7 lobes that end in spines.
Distinctions: Resembles the widely available Pin Oak, Q. palustris- but the acorns are larger on nutall oak. This is a fast growing tree with an open crown.
Ecology: Limited native range in parts of Louisiana, Mississippi, and east Texas. Likes waterlogged soils of floodplains