Central Texas Tree Field Guide

Some arguments about trees in Austin turn out to be arguments about names. A common name here often covers two different species that carry different risks and want different treatment — so this guide names the species behind the name, and groups the entries by what you actually want the tree to do.

Three of them are worth spelling out.

• Live oak is two trees. The escarpment live oak,Quercus fusiformis, is the one that forms the interconnected root systems oak wilt travels through. The coastal live oak, Quercus virginiana, grafts into those networks far less often — meaningfully lower risk, not an exemption. They also want different pruning: a sound escarpment tree gets deadwood and clearance, not reduction, while a coastal one with structural defects is a candidate for cabling and proper reduction pruning as the start of a multi-year structural program rather than a single job.
• Cedar fever is one juniper, not the other. It isJuniperus ashei, the ash juniper, which makes up roughly a third of the trees in the Austin area and peaks in December and January. The eastern red cedar people are warned off planting is Juniperus virginiana, and it grows nowhere near that density here. The two pollens are closely related and cross-reactive rather than the same; the argument is density and habitat, not that one is allergen-free.
• Redbud is a choice between two. Mexican redbud is the one most native to Central Texas — shorter, and more reliable over time. Eastern redbud suits central and east Austin with irrigation.

Splitting hairs between native and adapted trees that a layperson sees as the same green leaves and brown bark is usually not worth a homeowner's afternoon. It is worth it in these three cases, because each name hides a different decision: what to plant, how to prune it, and whether to worry.