AgCenter: Southerners love live oak

HAMMOND — Have you noticed that Southerners have a love affair with the live oak? And rightly so! Noted for its strength and longevity, this stately tree was one of the major tree species that survived the wind and flooding of Hurricane Katrina. It is also one of the few trees that have a society of which all members (except for one human custodian) are live oak trees.
The Live Oak Society is a registry of more than 7,500 notable live oak trees found throughout the South. To become a member, a live oak must have a girth (waistline) of 8 feet or greater. Girths over 16 feet are classified as centenarian. Registation informations is available online from the Louisiana Garden Club Federation — www.lgcfinc.org/live-oak-society.html.
The LSU AgCenter Hammond Research Station has seven registered live oaks with seven more in-waiting.
The most notable of the centenarian trees are located at the front entrance to the station.
Winter is a great time to provide care and maintenance to your live oak trees. From selecting trees at the garden center to planting, pruning and fertilizing, this is the time of year for live oak maintenance.
If you intend to plant a live oak, select a tree with a well-developed central leader system. And be sure the tree was properly pruned at the nursery. Proper pruning at a young age is important for live oaks long term. Most home gardeners should plant trees growing in 3- to 15-gallon containers, although you can purchase live oaks that are much larger. It is hard, however, for an average homeowner to handle planting trees larger than those growing in a 15-gallon container.
When planting, be sure to follow LSU AgCenter tree-planting recommendations:
—Make the planting hole the same depth and two to three times as wide as the container in which the tree has been growing.
—Make the sides of the planting hole rough, not smooth.
—Refill the planting hole with the same soil that came out of it.
—Do not amend this backfill soil with compost, pine bark or similar materials.
—Water the tree during the planting process to eliminate dry pockets that will desiccate the new growing roots.
—Mulch trees after planting.
Be sure to give your new live oak tree adequate room. Most of the time, live oaks are now planted on 30-foot-by-30-foot spacing. This is, however, way too close. You also see live oaks planted on 60-foot-by-60-foot spacing. This is OK. But ideally, live oaks need to be planted on 90-foot centers.
We all see live oaks in front yards that have basically no room for a tree this large. Also, live oaks routinely are planted between streets and sidewalks. Once again, this is the wrong tree in the wrong place. Be sure to plant live oaks where they have room to grow and do what they want to do. Fertilizing live oaks is not recommended the first year after planting. You can start a fertilization program thereafter.
Live oaks are one of our most important trees, so if you have one, provide proper care.
You can see more about work being done in landscape horticulture by visiting the LSU AgCenter Hammond Research Station website at www.lsuagcenter.com/hammond.
--By ALLEN OWINGS
LSU AgCenter
horticulturist