In order to give some guidelines for which trees to plant with success in the area, this article focuses on tree species native to the area. A separate article focuses on non-native species that grow and thrive in the Austin area, and then to non-native species that thrive here.
I am constantly asked for planting recommendations in the Austin area. Many people plant the wrong trees in the wrong place. For example, water loving trees (riparian or swamp species) are planted in dry, sunny areas, often close to the road where radiant heat exacerbates their decline. Often trees that cannot survive in rocky soils are planted in heavy limestone. Certain trees, such as loquats or certain palm varieties cannot handle frost in the winter without being wrapped up.
Commonly planted native trees
Live oaks: The most common native Texas tree to this area is of course the live oak. Although the common native live oaks such as the escarpment and interior live oaks are the two common local species, the now introduced Louisianaor coastal live oaks, Quercus virginiana, are now cross-pollinating with the local species and creating hybrid live oaks.
The native live oaks are a stronger wooded tree, but much slower growing. By contrast, the virinianas are fast growing and weaker wooded warm winter live oaks. These trees are commonly planted by nurseries and builders in new neighborhoods. The hybrid species the nurseries are now selling have both the characteristics of faster growing live oaks with slightly stronger wood as well. Live oaks can live for hundreds of years under ideal conditions, with some local trees surviving for up to 500 years or more!
Cedar Elms: The second most common native species to this area is the cedar elm. This native, drought tolerant species grows among the live oaks, ashe junipers (cedars) and other trees in greenbelts. These elms have smaller leaves than other elm species, with thicker cuticles to help with the hot, dry climate. They grow thicker than the live oaks, have weaker wood physiologically, and are also less adept at compartmentalizing rot, which leads to more decay pockets in older trees that tend to be more susceptible to storm damage. In spite of this, the cedar elm is considered the next most valuable tree to the live oak as it lives for up to 100 years or more under ideal conditions and adds considerable value to a property.
Southern red (or Spanish) oaks: I consider the Southern red oak family the next most common local native tree. Again with much hybridization, the local southern red oak is called the Spanish oak. These trees have adapted to the local limestone slopes and are able to access the iron in the limestone. They live for well over 100 years, especially in deeper soils where they can get quite large, but are mostly found on rocky ridges and slopes where they usually stay smaller due to poorer soil. Spanish oaks growing in these conditions may be much older than they look.
Because they have thin leaves with larger surface area, Spanish oaks do much better in areas where they have shaded root zones and in greenbelts as part of a thick forest canopy. Where the sun bakes the roots, and as edge trees (see Knowledge Center article on Spanish oaks), they often get bacterial leaf scorch from too much heat and inability to retain enough water. I recommend planting them in landscaped rocky areas where little else will grow, and where they can get more water in the summer due to sprinkler irrigation or hand watering, and preferably in shady areas, although they will also thrive in deeper soils.
Texas ash: With a rounder and typically deeper green leaf, this much smaller and relatively short-lived native tree typically is characterized by a single dominant leader. Relative to other trees, this tree is fairly thin and scraggly and one of the shortest-lived native greenbelt trees in the Austin area. They typically have a 15-20 year life cycle (or less). For this reason, you can often see many dead Texas ash trees within local greenbelt slopes. These trees grow slightly larger and live a little longer in deeper soils with irrigation, but due to their shorter life span typically lose out to other species in most local landscapes. Some native plant purists love them but not many people want to invest in ash trees versus longer lived, more valuable species such as oaks or cedar elms.
Rarely planted native trees
Escarpment black cherry: This is an interesting but rarely planted native species. Most of these trees I encounter are in natural greenbelt areas on slopes or ridge tops. We have pruned them from time to time. They have interesting bark, with lenticels (small holes that act as gas exchange) on the bark that give them an interesting look. They don’t produce fruit, and are not exactly plentiful, but do give some additional diversity.
Due to the limestone here, we have a fairly simple oak/elm/cedar forest here for the most part, with a lot of native understory plants. Some smaller trees, such as the Mexican buckeye are also present, but most of the local plant diversity seems to be in smaller trees and shrubs, and one can learn quite a few of these species by walking trails at Wild Basin, for example.
Overall and in generally favorable conditions, meaning in times of average rainfall and temperatures, any of these trees should do well if planted at your home or business. Of course it’s important to give a newly planted tree extra attention — water and often fertilization — to help ensure its long-term health and growth.