Things You Should Know About Oak Wilt

Big Oak Tree — Fenton, MO — Baumann Tree
Oak trees are a beautiful addition to your Missouri home, but they are more prone to a serious disease this time of year. Oak wilt disease is highly prevalent in Missouri. If you don't take precautions to care for and protect your oak trees, you could end up most, if not all, of them. Discover more information about oak wilt, its symptoms, and prevention so you can take steps to keep your oak trees healthy.

What Is Oak Wilt?

Oak wilt is an infectious fungal disease that attacks your trees' water-conducting system. It primarily enters through cuts and wounds or through grafted roots with an infected tree. When wounded, the sap attracts insects that bring the fungus from other infected trees.

While any oak is a potential victim, the black oak family is the most susceptible. The most sensitive member of this family is the red oak. Red oaks tend to graft roots with other close-by red oaks. So, when the infection affects one, it spreads quickly through the root system if not detached.
White oaks are more resistant, but they may succumb to the disease after a long period of infection.

What Are Signs of Oak Wilt?

The earliest signs of oak wilt are dying-off or discoloration of the leaves and branches in the crown. In red oaks, infections often spread fast, and you will see severe deterioration within a few weeks. Red oaks die quickly, while other species may take up to a year. White oaks may take much longer to show symptoms.

Another sign of oak wilt is spore mats and pressure pads. You can usually find these mats on the trunk, and they usually appear when your tree is near death. Spore mats can also occur on oak firewood. These mats emit a sweet scent that attracts insects such as the sap beetle.

How Does Oak Wilt Spread?

Besides spreading through the root system, oak wilt also spreads from insects transporting the fungus. When an oak has an open wound, its sap rushes out to heal it. This wound attracts insects like the previously mentioned sap beetle. These beetles find the sap quickly and will often have found your tree before you notice the injury.

How Can One Protect Trees from Oak Wilt?

To reduce your tree's chance of oak wilt, don't trim them between April or July or when you have stretches of summer rain. The trees are the most active at this time and more likely to give a defensive response to injury. Trim your oak trees during dormant times in the late fall and winter.

Protect your trees from accidental injury from gardening tools and equipment. Check your trees for wounds often. If you see any wounds, even small ones, seal them up as soon as possible. Then, keep an eye out for any signs of infection.

Can One Save a Tree With Oak Wilt?

Unfortunately, no cure exists for oak wilt. If confirmed for the disease, the tree will die. However, you can protect nearby trees through special fungicide treatments. You or an arborist can also sever any possible root grafts with other trees.

Do not try to remove the tree while it is still alive. When you try to remove a live infected tree, you increase the chance of fungal spore release. Remove the tree once it is fully dead. Dispose of the wood properly to eliminate spore transmission.

Oak wilt disease is a serious disease that can potentially cause problems for all the oak trees on your property or even your neighborhood. Before you assume your tree has oak wilt disease and needs removal, contact an arborist for an assessment. Baumann Tree can check over your oak trees and determine a course of action. Call us today, and we will send over someone to check over your tree.
Man examining a leaf with brown spots, indicating disease or pest damage.
August 13, 2026
Learn tree disease treatment options for St. Louis, MO trees. Baumann Tree's ISA-certified arborist identifies EAB, oak wilt & more. Get an inspection today.
An arborist in high-visibility gear and a hard hat examines the bark of a tree trunk.
August 13, 2026
Learn why certified arborists matter for St. Louis trees. Baumann Tree offers ISA-certified expertise for safe, informed tree care. Request a quote today.
Close-up of a stump grinder machine removing a tree stump with wood chips flying in the air.
August 13, 2026
Compare stump grinding vs. full tree stump removal for your St. Louis property. Baumann Tree offers free estimates and expert service. Call today
Fallen tree causing storm damage to a residential property after severe weather
July 20, 2026
Storm damage tree service in St. Louis, MO — Baumann Tree outlines safety steps, insurance tips, and when to call. Get a free estimate today.
July 14, 2026
When homeowners and businesses need dependable tree service in St. Louis, MO , they need a company that puts safety, experience, and customer satisfaction first. Whether you're dealing with a hazardous tree, storm damage, overgrown branches, or routine tree maintenance, Baumann Tree has been providing professional tree care throughout the St. Louis area for more than 30 years with an ISA Certified Arborist on staff.
Tree stump in green grass.
June 30, 2026
Delve into the benefits of stump grinding and shrubbery removal and why it is crucial to hire a professional to do the job effectively.
June 29, 2026
Baumann Tree offers Tree Service St. Louis, Tree Removal, Tree Trimming & Certified Arborist services in St. Louis, Wildwood, Frontenac, Chesterfield & Eureka, MO. Call 636-375-2812 for expert tree care.
Person climbing a tall tree in a lush green forest, seen from behind with safety gear.
June 25, 2026
Learn why hiring a certified arborist in St. Louis, MO matters. Baumann Tree offers ISA-credentialed tree care. Call for a free estimate today.
June 9, 2026
Ensure tree health & safety with expert services. Call 555-555-5555 for tree removal & trimming in St. Louis, MO.
A man is removing a tree.
May 28, 2026
Protect your property by recognizing critical tree removal warning signs. Learn how to spot structural defects, root damage, and decay before it’s too late. Baumann Tree offers expert tree service. Call for a free estimate.