As part of our four-point plan to improve electric reliability in the communities we serve, DTE Energy has an aggressive program of tree trimming, both targeted and also as part of our regular maintenance cycle. Why is this important? We know that half the time our customers spend without power is due to trees and branches coming into contact with our electrical equipment.
We trim trees during all months and in most any weather condition, but in Michigan we must take extra precautions with Oak trees to avoid Oak Wilt, which can kill a tree within a matter of months. Let’s discuss this further with DTE Arborist A.J. Smith II, who oversees all planning for our many tree trimming crews.
Q: Tell us what Oak Wilt is and the damage it can cause?
A: Oak Wilt is a forest pathogen that’s been working its way through Michigan. It’s a fungal infection that attacks the cells of oak trees, including the species in our region. While Oak Wilt affects all the members of the oak family, which in Michigan the White Oak and Red Oak, it really impacts the red and its varieties much more strongly. It can be devastating. Typically, we see trees dying about two years after first being infected.
Q: How does an oak tree become infected? Is there a common carrier?
A: Yes. Oak Wilt is introduced to the tree via one of two primary ways: It can be carried from an infected tree to a new host tree by a beetle that has been feeding on the fungal body. Alternatively, it can enter a tree through windblown spores, if there has been recent “wounding” on the tree, which is where most of the interest comes in from our tree trimming industry.
Q: Red oaks— why are they more susceptible to dying than the white oak?
A: It’s interesting because of the strength of the white oak tissue. They have this specialized cell in their wood called tyloses, which essentially swells up and closes the vascular tissue inside of the tree itself. If you are a fan of wooden shipbuilding or even whiskey, many of the barrels and boats will be made from this white oak wood because that tissue ends up sealing them up watertight. Same with the living tree, so it makes it much harder for the disease to take hold with a white oak. But not so with their cousins, the red oak. Since it lacks those same cells of the white oak that seal up, the Oak wilt infection can run rampant through their conductive tissue rather quickly. By that point, it’s too late.
Q: We know there is a specific season for transmission of Oak Wilt. Do we consider that when planning tree trimming?
A: Absolutely. The transmission season begins on or about April 1 every year. We always work closely with the state of Michigan, the Michigan DNR and an organization called the Michigan Oak Wilt Coalition to inform our trimming practices each year. Essentially, during the high-risk time of April through to about mid-July, we stop trimming oak trees entirely.
Q: What if there is a definite need to cut, like during extreme weather and storms with large outages?
A: Obviously, that can happen with any emergent situation where branches break, or we have storm restoration that needs to be done. But during that time, we will not put a saw to an oak tree unless we absolutely must, and if we do, we will seal up the cuts made on that tree with a latex based paint that’s impervious.
Q: It’s like an emergency tree repair that solves our issue with branches on equipment but also keeps the infection from the tree, or being carried to other trees? Like an oak triage?
A: That’s exactly what it is, and when absolutely needed, it’s very effective as well.
Q: You said it’s rolling now through Michigan, but how did it get here? Or has Oak wilt, in some form, always been around us?
A: It’s a non-native pathogen to our region. But with the climate gradually warming, both the range and the time period for which the oak wilt can spread is becoming larger and longer as the environment becomes, unfortunately, more hospitable to it. We have seen an uptick in it over the last decade or two.
Q: We discussed airborne spores and beetles as being the primary carriers of oak wilt, but is there another way that humans can perhaps inadvertently become spreaders of the infection?
A: For sure. In Michigan, so many of us love to travel and make a campfire. But please don’t transport oak from your home area to any another place in the region. It’s also important to not bring any firewood home with you from a weekend trip or vacation, especially from April 1-July 15. That can spread disease, as well. When you travel, simply get your campfire wood when you arrive and either burn it or leave it there for someone else to use after you go.
Q: DTE has a made Right Tree, Right Place a priority for any plantings that may be near our electrical equipment. I would imagine that’s also important when it comes to Oak wilt?
A: Totally. Look, we know oaks are beautiful. They help provide us with the air we breathe, shade in the summer, habitats for animals and are great to look at. That said, if you are spending the money and planning to enjoy that tree for many years, why take a chance with having it close to our equipment where it can cause power interruptions or need trimming, and thus increase the potential chance of being infected with oak wilt? It just takes a commonsense approach and awareness to get to a better outcome all around.
Q: What general advice would you like to close with for our customers who have oak trees?
A: First, always know if they are Red Oak or White Oak. One way to tell the difference is reds have very pointed leaves, and the white trees have more rounded leaves. If they are the red variety, use proper caution during oak wilt season. If you’re planning any kind of trimming, always consult first with a professional arborist for their expert advice at keeping your oaks, and those of your neighbors, healthy and beautiful for years to come.
For more information on the important tree trimming done by DTE to improve electric reliability, visit the tree trimming page on our main website. For more information on the dangers of oak wilt and how to prevent its spread, visit our partners with the Michigan Oak Wilt Coalition.