WHAT TREES ARE AFFECTED BY OAK WILT? WHAT IS THIS LETHAL DISEASE KILLING MY OAK TREES?
Oak wilt is a lethal disease that affects both the Red and Live Oaks. 100% of all Red Oaks die when infected with Oak Wilt, while Live Oaks have an 85% mortality rate. Recently, Oak Wilt has crept into rural Central Texas areas such as Waco and Moffat, demanding treatment and prevention from responsible property owners. Trees from the White Oak group can be infected with Oak Wilt, but research shows that it has little effect on this oak group.
We have found in central Texas the main trees that are infected are live oaks. When oak wilt hits it can kill a tree in as little as 2 weeks up to 6 months. Most don’t survive. It is a rare thing for red oaks to be infected in this area. White oaks seem to not be an issue here. Also, Central Texas is the hot bed of oak wilt in the country with oak wilt in about 25 states so far.
How Oak Wilt Kills
The disease is caused by the reaction of susceptible oaks to the fungus Ceratocystis fagacearum. The fungus causes the water-conducting (vascular) system of the tree to become clogged, resulting in the tree wilting and dropping its leaves (thus called oak wilt).
The disease/fungus (Ceratocystis fagacearum) causes a reaction in susceptible oaks. The fungus clogs the water-conducting (vascular) system of the tree. One of the results are the tree wilting and dropping its leaves (thus called oak wilt). Layman’s terms, it works like plaque in your blood vessels clogging them up. Live Oaks generally die within 1-6 months, although some have been known to linger for years.
The type of oak tree also determines how long it takes before a tree dies from the Oak Wilt. Red Oaks have the shortest life expectancy of the oaks when infected. Most infected oaks can die if not treated within weeks or months. Red Oaks turn brown very rapidly, usually within one week. Live Oaks generally die within 1-6 months, although some can linger for years.
What Will My Tree Look Like?
Live Oaks appear thin and yellow/orangish from a distance, usually with an abundance of leaf loss at the top of the tree. They tend to look a little different color green than the other trees, not as bright green.
Red Oaks turn brown very rapidly when infected – usually within one week. The leaves wilt and turn brown, moving from the margins inward, and may appear dry, as shown on the right.
Leaves at the tip of the branch may wilt first. It can be difficult to distinguish from a normal leaf drop in autumn. After the death of a tree, wood may form fungal mats (spore-producing structures) under bark. Firewood can also form fungal mats.
Live Oaks appear thin and yellowish from a distance, usually with an abundance of leaf loss. Most of the 15% that survive look ragged. The good thing about Live Oaks is that they are not known to form spore-producing fungal mats.
When an oak tree has oak wilt, it transmits the fungus through the roots using grafts to surrounding trees. Oak Wilt keeps spreading until the entire mott or neighborhood is infected with hundreds of dead and dying oaks. It usually spreads around 75 to 150 feet per year by the roots. The larger coastal live oak’s roots reach out much further.
How Is Oak Wilt Spread?
1. When an oak is infected with Oak Wilt, it transmits the fungus through root grafts to surrounding trees. Oak Wilt can keep spreading until the entire neighborhood is in an “oak wilt disease center” with hundreds of dead and dying oaks. It usually spreads around 75 to 150 feet per year in this method.
2. When Red Oak fungus mats enlarge, they crack the bark and emit a fruity odor that attracts the Sap Beetle. These fungus mats are also known to grow on Red Oak firewood. When the beetles feed on the mats of the infected tree, fungus spores adhere to their bodies. As the beetles move from diseased trees to the wounds on healthy oaks, the disease-causing spores are transmitted to a new host — your tree. The Sap Beetle is inactive during extreme temperatures. Wounds on your Oak Trees should be painted to prevent the beetle from spreading the fungus to the fresh wound. These wounds can be caused by regular trimming, branches rubbing on other branches, deer horns, and even buildings.
3. Another way the fungus spreads is when a trimming tool is used on a contaminated tree and then on a healthy oak tree without being cleaned in between. It is very important to sanitize tools before cutting on other trees. Sanitizing can be done with a bleach solution, Lysol, or alcohol.
4. Squirrels, Birds, Insects, Etc., Can Carry The Oak Wilt Fungus From Tree To Tree.
Best Time for Treatment
Because Oak Wilt fungus spreads rapidly and then infects, and kills your tree, timing is critical. The summer heat, combined with this fungus, can destroy a tree in days. Immediate action is imperative. Spring can be a critical time for treatment because of the beneficial growth of new foliage. Insects can move the fungus from tree to tree sometimes miles away as the wind can blow them around. Tree trimmers can move it by not cleaning their tools. It is especially important to sanitize tools before cutting on trees. Sanitizing is best done with a bleach solution, Lysol, or alcohol. Sealing their cuts as they go along with the cheapest spray paint works well. Deer rutting on trees can move the fungus. Woodpeckers moving from tree to tree… Squirrels …. The list goes on and on.
I have seen oak wilt on a bunch of ranches that have it every 150 yards apart. I have no idea how it moved like that. Or oak wilt in an area with the closest oak wilt miles away.
Our exclusive BioGreen system can add as much as 50% more foliage to an affected tree. When you suspect your tree is infected or threatened by surrounding trees, contact us for a consultation and assessment. Our system is effective year round.
Call us today at 512-712-6100 to rejuvenate, strengthen and restore your trees!