SAN ANGELO The pecan may be the state tree of Texas, but if there’s a runner-up, it’s probably the live oak.
“No other tree is so widely planted as is this popular oak variety,” said John Begnaud, Texas Cooperative Extension horticulture agent for Tom Green County.
“Green is always a welcome color in dry west Texas landscapes,” he said. “The same holds true even in wetter climates during the grey cold days of winter. Other than the pines which are conifers, or needle producers, few large trees can deliver evergreen foliage the way live oaks do.”
Live oaks are not deciduous, according to Begnaud. They don’t drop their leaves for a winter rest period. This evergreen oak’s leaf-drop is very brief, unlike most oaks which remain bare all winter.
Live oaks are drought-tolerant Texas natives that are well adapted to a wide range of soils. Although considered slow growers, these trees can grow quickly if they are watered and fertilized two to three times a year when they are young.
Live oaks are true giants, Begnaud warned. In home landscapes, plant them no closer than 20 feet from the home, 15 feet from solid surfaces and at least 35-40 feet away from the nearest tree, he advised.
“The No.1 complaint about live oak trees is the mess they make from dropping leaves, acorns, occasional aphid sapping and roosting birds,” Begnaud said. “These reasons and their size make planting them away from water features and outdoor living areas a good idea.”
The trees’ thick multiple-branched canopy provides cover for birds and animals, Begnaud said. Most hanging deterrents, such as rubber snakes and owls, usually don’t impress roosting birds enough to make them move. Selectively pruning crowded, rubbing or duplicated branches makes birds feel less safe and exposed to cats and other predators.
Pruning also lets sunlight through the canopy and helps turf grow under the trees, he said, adding that February is the best time to prune live oaks. Large, old trees benefit from occasional pruning, but, unlike younger trees, need no fertilizer unless stressed from disruption to the root system.
Ideally, pruning should end before leaf shed and warm spring weather, especially in oak wilt areas, Begnaud said.
Cold weather may turn live oak leaves brown, but Begnaud said not to worry, because the discolored leaves will drop in early spring. New leaves sprout and grow in spring and early summer, but unlike many evergreens, live oak leaves only last a year.
“This leaf shed and re-leafing can be unnerving to some and is sometimes so dramatic it leaves the trees naked for one or two weeks in the spring,” Begnaud said. “Genetics and environmental influences determine the degree of live oak leaf color, size and shedding.”
Root sprouts or suckers can be a real problem with some live oaks. A considerable amount of research has been done on the topic with no real answers yet, he said.
“To date, there are no repellants, hormones or chemical sprays that reliably suppress or remove these suckers without harming the mother trees,” he said. “Hand-grubbing or deep-root pruning can reduce these suckers for a few years, but they come back. Planting ground covers beneath these root sprouters, such as Asian jasmine, which has a similar leaf form, can help hide these suckers.”
Now is the time to plant container and balled and burlapped live oaks, Begnaud said. It’s also a good time to dig trees from pastures or relocate volunteer trees.
Just remember to give these mighty oaks plenty of room to grow, Begnaud said. The result will be a majestic natural treasure that should last for generations with a minimum of care.