AUSTIN, Texas
— The big, beautiful live oaks that line your street and shade your home aren’t
indefensible. There’s a silent killer that at this very moment could be
creeping down your block, one yard at a time.
Considered an
epidemic throughout Central Texas, oak wilt is one of the most destructive tree
diseases in the United States. The infectious disease spreads in the spring,
killing all trees that share its name, with red oaks and live oaks most
susceptible.
“A live oak is
a great survivor against everything that gets thrown at it from wind damage to
drought to insects and other diseases, but it’s a poor survivor with oak wilt,”
said Texas A&M Forest Service Regional Forest Health Coordinator Jim Houser
in Austin.
Oak mortality
has been noted since the 1930s, but oak wilt wasn’t confirmed as the cause
until the late 1970s. It has since been found in 76 counties — principally in
Central Texas though it’s crept as far as Amarillo and Houston.
An infected
oak can spread the disease to surrounding oaks via their interconnected root
systems. When that happens, the only way to stop further spread is by digging
trenches to break the root connections.
Oak wilt also
can be spread from February through June via sap-feeding beetles, which eat
spore mats produced by infected red oaks. The disease is spread when those
insects fly off to feed on a healthy red oak or live oak with a fresh wound.
Diseased live
oaks do not produce the same spores but they can become infected by them.
“We’re talking
about trees that have been in the landscape for a century or more. We don’t
replace those trees overnight,” Houser said, adding that the death of such
majestic trees can lead to drops in property values. “Preventing oak wilt is
the key.”
A wound is
created any time bark is removed and wood is exposed. That can happen with the
simplest of tasks — planting flowers, pruning or even pushing a lawn mower over
a bare tree root.
That bare wood
produces sap, which attracts the sap-feeding beetles, Houser said, stressing
the importance of avoiding wounds in the spring, painting tree wounds year
round and destroying diseased red oaks that may harbor spore mats on which
sap-feeding beetles may feed and spread the disease.
“You
don’t want to have to manage oak wilt. That means you have it. You want to
prevent it from happening,” said Houser, explaining that there was no cure for
the disease. “An ounce of prevention is worth it to avoid starting oak wilt
disease and killing your trees.”
For more information about oak wilt and maps detailing which counties
are affected, visit www.texasoakwilt.org, Texas
A&M Forest Service www.tfsweb.tamu.edu have
a tree tested for oak wilt through the
Texas A&M Plant Disease Diagnostic Clinic & Laboratory at www.plantclinic.tamu.edu. You
may also contact your local municipal forester.
###
Photos of Oak
Wilt and its symptoms available at https://www.flickr.com/photos/texasforestservice/albums/72157693997774934
Contact
Jim Houser, Regional Forest Health Coordinator in Austin
512-339-4589, jhouser@tfs.tamu.edu
Communications
Office in College Station
979-458-6606 office, newsmedia@tfs.tamu.edu