It stands as sturdy and stout as Mount Rushmore yet as beautiful and graceful as the sea. The oak tree. It’s the large, robust trunk and strong, powerful branches that house quantities of round-shaped leaves and thick, leafy foliage. Oak trees are in abundance in the mitten state and symbolize the strength and pride of our heritage. They are part of the deciduous family, and many live up to 200 years or more. But there is a disease rippling through them, threatening our Michigan landscapes, parks, and forests. This disease is called Oak wilt, and it costs the state billions in agricultural costs.
Today, PPM Landscape Contractors takes a deep dive into this horrendous disease, how you can tell if one of your beloved oaks has been affected, how to prevent it, and what you can as a Westland area home or business owner can do to combat it.
Oak Wilt Defined
First reported in the United States in the 1900s, Oak wilt, or Ceratocystis fagacearum, is a fungal disease carried by beetles that feed on the tree’s sap. It moves through the tree’s vascular system and is deadly because it cuts off your tree’s water and nutrient supply. The lack of nutrients and water causes leaf discoloration, wilting of the tree, and the leaves to fall off. Eventually, the disease can cause the oak tree to die.
Two Types of Oak Trees in Westland
Oak trees in Michigan can be divided into two main groups: red oaks and white oaks. Generally, red oaks have pointed leaf lobes, and white oaks have rounded leaf lobes. While both types of oak trees can become infected with oak wilt, the overall process takes longer in white oaks with fewer symptoms. Red oak trees, on the other hand are much more vulnerable and quicker to succumb to illness and death.
Symptoms of Oak Wilt Include:
If you see any of these symptoms in your oak trees, your plants might be suffering from oak wilt.
- Leaves curling up
- Discoloration in leaves to light green, bronze, or tan color, beginning at the edges and moving in towards the center of each leaf
- Brown or black stain in the sapwood of wilted branches
- Vertical cracks in the bark of the tree that have mats of fungus spores underneath
- Quick defoliation of the tree, even in late summer
- In white oaks, leaves will turn light brown or straw-colored, with discoloration moving from the tip of the leaf to the base
- In white oaks, leaves will also curl up but usually won’t fall off the tree branches
How Oak Wilt Spreads Throughout Westland
Oak wilt is spread in a variety of ways, making it even harder to treat. Ways in which oak wilt spreads include:
Oak wilt is carried by an invasive beetle called Nitidulids, commonly referred to as sap beetles. These sap beetles are attracted to a fruity odor terminating from root grafts and wounds created from pruning. This unique smell attracts the sap beetles, which feed off the fungus on top of the bark. The fungal spores stick to their tiny bodies infecting every tree they attach to hereafter. Fortunately, sap beetles are not active when your trees are dormant.
The most common way oak wilt is spread is through the intermingling of an infected tree’s roots with the roots of an unaffected tree. The roots of most trees spread way beyond what we can see above ground. Most spread out like spider webs reaching out in all directions. When an infected tree’s roots intertwine with those of a healthy oak tree, it sends out shockwaves infecting the tree it touched and all those around it. The only time a tree is not in danger is when it is completely dormant.
Fungi tend to live on firewood well after being cut from an infected tree. When that firewood is moved from one place to another, the fungus may spread to uninfected hosts.
Oak Wilt Prevention
When it comes to preventing oak wilt, the best way to prevent this horrible disease from occurring is by pruning your cherished oak trees only during winter dormancy. In Westland, that is typically between the end of October and the beginning of April, although each year varies. Therefore, it’s best to check with or have a professional handle your pruning. Pruning during dormancy will give your trees time to heal before the fungus is able to attract sap beetles.
If you must cut limbs or branches during the active growing season of April through October, make sure all wounds are sealed with a tree wound dressing, clear shellac, or latex paint. You can purchase tree wound dressing at any local hardware or home good store. And always clean your tools with alcohol or bleach between cuts to ensure any residual fungus has been removed.
Once Oak Wilt Is Discovered on Your Westland Property
Because oak wilt can mimic the symptoms of other tree diseases, first be sure to have the trees properly diagnosed. Properly obtained and handled branch samples can be submitted to a lab such as MSU’s Diagnostic Services, or you can contact PPM Landscape Contractors for a full analysis. If caught early, disrupting root grafts and the use of fungicides can help stop the spread. If the damage is extensive, the tree may have to be removed. And because of underground transmission, all root connections must be severed to protect any uninfected oak trees.
Leave it Up to the Professionals. Call PPM Landscape Contractors for All Your Tree Trimming and Pruning Needs
When it comes to your beloved oak and other lawn ornamentals, don’t take chances. Leave the tree trimming and pruning up to the professionals. PPM Landscape Contractors will send our trimming specialists to come to your Westland property and advise you on the best care and trimming options for your trees. Our pruning and shaping service will encourage the health of your oak and other trees while creating a polished, uniform look.