If your oak tree is diseased, wilting, or dropping leaves, it can be saved if you act quickly. Although oaks are hardy trees, they can still be afflicted with tree diseases. To save a dying oak tree, employ the following tactics:
- Prune and discard any diseased branches.
- Spray diseased areas with fungicide.
- Inject fungicide into your oak tree.
- Fertilize your tree.
- Mulch near the base of your tree.
- Ensure your tree is not overwatered. Dig drainage ditches if the tree is in boggy ground.
By following these tips, you can save a tree from oak wilt, oak leaf blisters, and fungal infections, ensuring your oak many healthy years to come.
How to Tell if Your Oak Tree is Dying
What does a diseased oak tree look like? There are a few signs your tree is dying. An oak that is afflicted with oak wilt will have leaves that turn brown and fall off prematurely. Oak leaf blisters manifest as raised yellow or brown bumps on healthy leaves. Other signs of disease include cankers, which are areas where the bark has died and fallen from the trunk.
- Dead branches
- Leaf blisters
- Prematurely browning/falling leaves
- Cankers (dead bark falling off the trunk)
- The presence of pest insects and/or woodpeckers
Dead branches and diseased portions of a tree invite carpenter ants, termites, and other insects. If you see signs of these pests or the animals that feed on them (such as woodpeckers), it’s a sign that your tree is unhealthy and needs to be rescued.
7 Tips to Save Your Dying Oak Tree
Healthy trees can be attacked by disease due to excessive water, a fungal bloom, or branch breakage that opens a “wound” in your tree. However, your diseased tree doesn’t have to turn into a dead tree. Here are the best ways to save your oak.
Remove Diseased Branches
It’s essential to use a sharp pair of pruning shears or a pruning saw to remove dead, decayed, or diseased oak branches. If left to their own devices, these diseased areas can infect the rest of the tree.
- Identify dead and diseased branches.
- Remove the branches with pruning shears or pruning saw.
- Clean pruning tools with alcohol after use, to prevent spreading the disease to other trees.
- Do not apply pruning sealant to areas where you removed a branch.
Never use pruning sealant after cutting off a tree limb. There are several shocking reasons to stop sealing tree limbs after pruning, including the fact that sealant increases the chances of tree disease. Wear gloves while working with diseased trees and clean all cutting tools with alcohol after use. Otherwise, using the same tool on other trees (or healthy parts of the same tree) may spread the disease.
Dispose of Dead Branches and Leaves
After pruning, gather pruned branches and any fallen leaves. These should be disposed of immediately, especially in the case of trees afflicted with oak leaf blisters. If these diseased remnants are left behind, they can reinfect your tree.
- Gather pruned branches and fallen leaves
- Dispose of diseased material as green waste or in a controlled burn.
Diseased branches can be discarded as waste, or they can be burned. Make sure to check your local guidelines before starting any outdoor fires.
Spray Diseased Areas with Fungicide
Trees afflicted with fungal diseases that permeate trunks, leaves, or large branches cannot be saved merely by pruning. Instead, you need to attack the fungus with an anti-fungal spray.
- Use an anti-fungal product to kill fungus attacking leaves, bark, and branches.
- Mix and use anti-fungal products according to the product label.
- Wear gloves, goggles, and mask when applying anti-fungal products. Keep children and pets safe from exposure.
A strong anti-fungal product will attack the disease that’s ailing your oak tree, giving it the best chance of recovery.
Inject Tree with Fungicide
Fungal infections can cause serious damage to oak tree trunks, even preventing the transport of water and nutrients up through the tree. If left untreated, this will kill the tree. The solution is to inject a strong fungicide into the tree using tree injectors. This will kill the fungus attacking your tree beneath the bark.
- If trunk bark is diseased, withering, or falling off, your oak needs tree injections.
- Use a fungicide designed for this purpose, like Quali-Pro.
- Inject the fungicide into the tree.
- Use tree injectors as directed by the manufacturer.
Tree injectors require you to drill a small hole in your tree, to allow you to insert the tip of the injector. This won’t cause lasting damage to the tree and allows you to inject fungicide that will rid the tree of disease. After successful injection, your tree will once again be able to transport nutrients from the roots to the leaves and branches.
Fertilize Your Oak
Now that you’ve gotten rid of the disease attacking your oak, it’s time to help it return to perfect health. A simple, all-purpose fertilizer such as Southern Ag’s 10-10-10 fertilizer is perfect for the job. Use as directed on the product label to feed tree roots and help your tree heal from its recent sickness.
- After disease treatment, apply 10-10-10 fertilizer to the entire area beneath the tree’s branches.
- Follow the product guide for fertilizer application rates.
An oak tree’s roots spread roughly as wide as its branches. So, it’s ideal to fertilize the entire area beneath the spread of the tree in order to deliver nutrients to the roots.
Mulch Around the Tree
To protect root health and prevent future infections, spread mulch at the base of the tree, making sure to leave a 12-inch (30 cm) space around the trunk of the tree mulch-free. This mulch blanket will protect roots and suppress weeds.
- Spread mulch around the base of the tree.
- Keep mulch 1 foot from the tree trunk.
Mulch mounded or piled up against an oak trunk can trap moisture against the bark, which may lead to repeat fungal infection. For this reason, never pile mulch close enough that it touches the trunk.
Ensure Proper Water and Drainage
Some tree diseases can be caused by poor drainage or excessive water in an area. This can result in struggling, wilting trees that are prone to disease.
- Observe the area around the tree after watering. If there is standing water or marshy ground, this can breed disease.
- Combat standing water by digging a drainage ditch to encourage water to drain away naturally.
Test the soil and observe after rain or watering. Is the ground boggy, with pools of standing water? If so, it’s time to dig a drainage ditch and draw that standing water away from your oak.
Can You Save a Dying Oak Tree?
A diseased and dying oak tree can be saved by pruning dead branches, discarding diseased branches and leaves, spraying or injecting the tree with fungicide, and caring for the tree with proper fertilizing, mulching, and watering tactics.
By removing the damaged portions of the tree and treating the cause of the disease, you give your oak tree a second lease on life. Now that you’ve stopped the disease, a little fertilizer and good drainage for the tree help it recover. Oak trees are resilient and will bounce back from the disease if treated quickly and carefully.