Understanding Oak Wilt and How To Prevent It
You may think of a mighty oak tree when this stunning tree variety comes to mind, and that’s because oak trees are incredibly robust and resilient. Interestingly, these trees stand up to 80 feet tall and can live upward of 600 years. Although oak trees can withstand many different weather and soil conditions, they aren’t invincible. Unfortunately, many oak trees fall victim to a disease known as oak wilt. Follow along to gain a better understanding of oak wilt and how to prevent it, so you can grow and nurture oak trees to their full potential.
What Is Oak Wilt?
Oak wilt is a disease that a fungus called bretziella fagacearum causes. This fungus invades the xylem, or water-conducting tissues, in oak trees. These tissues move water and minerals from the root system to the rest of the tree. Therefore, oak wilt can cause issues with nutrients, water, and sap flowing through the entire tree.
The black and red oak groups are more susceptible to oak wilt than the white oak group. Although there are no cures for this disease, you may be able to prevent it from spreading or occurring in the first place.
How Does It Happen?
If a tree has open wounds, the fungus is more likely to attach and multiply within the water-conducting tissues. Unfortunately, this invasive fungus spreads through the entire tree after some time, which disrupts the sap flow throughout the limbs.
After oak wilt infects one tree, it can spread in one of two ways to other trees nearby:
- The first way oak wilt can spread is through natural grafts with root systems of adjacent oak trees. Believe it or not, natural grafts can occur in oak trees up to 50 feet apart, as their root systems are wide and expansive.
- The second way oak wilt can spread is by beetles that feed on tree sap. The insects can transmit oak wilt fungus spores from infected trees to healthy ones.
What Do Infections Look Like?
To understand the signs and symptoms of oak wilt, you must first know the characteristics of a healthy oak tree. Healthy oak leaves are a vibrant green color with consistent texture, and bark growth cracks indicate positive growth. The tree tissue under the bark should be bright green or pink.
Now that you know what a healthy oak should look like, you can determine whether your oak trees are suffering from a disease. The first sign of oak wilt is wilting leaves that appear dull in color. After some time, these wilted leaves will turn a tan or bronze color toward the outer edges. The center of the leaves may remain green for a while, and the tree doesn’t always lose its leaves immediately.
Aside from the leaves, you may notice signs of disease in the tree’s bark. If you peel back the bark or look between the cracks, the outer tissue may appear black or brown. Even though the signs and symptoms of oak wilt seem clear, a positive diagnosis may require laboratory testing of samples from the tree or trees in question.
How Can I Prevent Oak Wilt?
Oak wilt is one of the most severe tree diseases, as it spreads quickly, and there’s currently no cure. With that said, preventative measures are the best ways to keep your oak trees healthy and robust. Follow along for a few tips for preventing oak wilt.
Consider Fungicide as Prevention
Because there is no cure for this disease, a fungicide may be an effective measure when it comes to active prevention. If you know another oak tree on your property has oak wilt, you may want to consider propiconazole injections for your healthy trees. This way, they may have the upper hand when it comes to resisting fungal growth and infestation.
Avoid Wounding Healthy Trees
Open wounds on healthy trees increase the risk of oak wilt; therefore, you should avoid pruning them during the sap-feeding beetles’ active season, which is February through June. When you do prune your trees, consider protecting the wounds by coating them with pruning paint. Furthermore, sterilizing your gardening tools between pruning each tree is another great way to prevent spreading infection through the open wounds.
Plant Oaks Far Apart
As previously mentioned, natural grafts in the root systems may occur in trees up to 50 feet apart. So planting your oak trees more than 50 feet apart effectively reduces the chances of oak wilt spreading to healthy trees.
What To Do When You Find Oak Wilt
Finding oak wilt can be daunting, as it can cause serious issues for every oak tree on your property. Although not having a cure for this disease is discouraging, there are a few immediate actions to take to salvage the healthy trees. If you notice it in the early stages, there’s a good chance it hasn’t spread very far yet—take action before more trees become infected.
Remove Infected Trees
After getting the positive results from the lab, the best thing to do is remove the infected tree or trees from the property. If you’re not confident in your ability to do this on your own, consider hiring a professional service to cut the trees down and dispose of them properly.
Handle Oak Firewood Cautiously
Cutting down the infected trees is the first step, but you also must be cautious about handling the wood. For instance, burning, debarking, or chipping large oak logs is the best way to prevent oak wilt from spreading after the tree is gone. In addition, avoid putting the chopped remains near healthy oak trees, as beetles can still spread the infection. If you have a pile of infected wood on your property, cover it with a hefty tarp and completely bury the edges. This will help prevent beetles from coming into contact with it.
Oak trees are mighty and robust—they’re able to withstand most other diseases and pests, but oak wilt is detrimental to their health. But now that you have a better understanding of oak wilt and how to prevent it, you can buy oak trees online and know how to care for them!