If you have trees and shrubs around your home or in your backyard, you know how unsightly it can be to have fungus growing out of them. Not only is tree fungus hideous, but it can also damage trees and shrugs by breaking apart their structural integrity and attracting additional pests. This can actually be quite dangerous, and we’ll explain why.
In short, tree fungus is something you should try to get rid of, or prevent, if at all possible.
Whether it is powdery mildew, oak bracket, black spot, verticullum wilt (all very common in North America) or any number of other tree fungi, there are a few things you can do about it.
Why Get Rid of Tree Fungus?
Over time, tree fungus will cause trees and shrugs to weaken, leaving the wood and leaves to be fragile and rotten. Although tree fungus isn’t dangerous for humans, the danger lies when the trees become too weak. If tree fungus has been feeding off large trees for a long period of time, their limbs or even entire body may fall over and collapse. This is dangerous for everyone in the surrounding area.
Aside from the potential of collapsing trees, tree fungus may also invite unwanted bugs and parasites. Depending on how far the trees and shrugs are from your home, the bugs and parasites may travel close to your home by invading other plants nearby. At this point, it can be real a health hazard as you never know the type of diseases these critters may carry.
However, most trees and shrugs that grow fungus will not directly harm humans, so you don’t have to worry about that. Fungus, in general, is not good for our health or the health of animals. It is best to avoid and eliminate it.
4 Primary Methods for Dealing With Tree Fungus
Easy DIY application. Treats many fungi if directions are followed.
Baking Soda and Water
Inexpensive and safe, using home ingredients. May not resolve all fungi.
Remove Affected Limbs
Isolated, visible fungus issues on a small part of the tree. (practice safety!)
Essential Oil enthusiasts. Functions much like fungicide.
Dealing with Tree Fungus
Now that you know why you need to get rid of tree fungus, let’s talk about how you can get rid of it. Here are four methods you can use:
1. Preventing tree fungus from growing
2. Baking soda and water
3. Clorox bleach and water
4. Cutting off infected limbs
Prevent Tree Fungus from Growing
The first and best method of getting rid of tree fungus is preventing it from growing in the first place. To protect your trees and shrugs, you need to understand when they are susceptible to tree fungus. Tree fungus can start to grow and spread because of things you do or don't do. Here are some tips:
Prune Trees at the Right Time
Many people prune (trim) their trees and shrubs to keep them healthy and strong. Pruning trees at the right time will actually make the tree healthier and more beautiful.
However, pruning them at the wrong time increases the risk of tree fungus. Very generally speaking, the best time to prune your trees is during the winter months while they’re dormant. If you prune trees during the warmer months, the wounds on the trees will not heal as fast as they should. This makes them vulnerable to catch diseases.
The kicker is that the right time prune a tree often varies based on the species, so it is important to do a little research. For example, pruning an oak tree in the early spring will increase the chances of fungus entering, while other species are best pruned during this time. Again, generally speaking, winter dormancy is usually a good time to prune.
Do not Over-Water Trees
Another way to prevent tree fungus is to not over-water them, especially if it rains a lot in your area. Over-watering of trees and shrugs will cause their roots to rot, and this invites fungi to colonize inside the rotting roots. Once the fungus starts to colonize, it will start moving upwards into the tree, and that’s when you will start to see the fungi spreading.
The best way to water a tree is to give it a deep soak about once a week. Watering a little daily means that the tree roots and base are constantly wet — a recipe for fungus! Note – on newly-planted trees, you need to water more than weekly. But once the tree is established, throttle back.
Use Sharp, Clean Gardening Tools
When you use the same gardening tools over and over, they start to get dirty and may pick up bacteria and parasites, especially if you don’t clean them. Then when you go to use these tools around your trees and shrugs, you’re directly inviting unwanted fungus spores to grow.
Dull tools can also be bad for your tree, because they do not give the tree a clean cut, causing the scar to collect moisture and dirt. They can also carry things that you just want to not have around, like poison oak spores (which can give you the famous poison oak rash even if you are nowhere near the plant).
Use a good, clean cutting tool. We like the Fiskars steel hand pruner (here on Amazon), a tried-and-true tree tool that can tackle branches as thick as about 1 inch.
Maintain Your Trees and Shrubs
When you have trees and shrugs around you, it’s important to always drain your soils properly and remove dead stems and leaves. You can also use preventative fungicides to prevent potential infections and diseases from growing.
Make sure that nearby plants and trees are not encroaching on your tree. Air flow is important. Trim back anything that interferes with your tree’s freedom, and be especially wary of vines that might start growing from the ground up.
Plant your trees in the right place
Every type of tree has planting instructions, and a situation that is best-suited for that particular tree.
Some trees like full sun in order to grow, others need to be protected from sun or they might get scorched. Some trees like to have plenty of moisture in the soil, others will die if they have chronic “wet feet”. It is not one size fits all.
I once planted a few trees in my backyard because I liked the species, knowing full well that I was going against the ideal planting instructions and the tree’s own requirements for light and water. I thought that with proper care, I could defy the odds and make these trees beautiful. As a result, the trees were stunted forever, and way more prone to disease than other trees.
Ways to Get Rid of Tree Fungus
Use a Fungicide Designed for Use on Trees and Shrubs
A good fungicide can do wonders on tree fungus. Just make sure it is designed for use in the landscape, on trees and shrubs.
The product we like is Natria Fungicide (find it here on Amazon) which seems to work on nearly any kind of outdoor fungus. Apple tree rust, regular leaf fungus, even lawn fungus. We also know from personal experience that it is quite effective on powdery mildew, the annoying affliction that likes to target popular magnolia trees.
It comes in either concentrate or an easy spray bottle. Just make sure you apply it when it is cool — on a not-so-hot day or in the evening. Applying during a very hot and sunny day could cause it to burn the plant or tree it is being applied to. You also need to really saturate the tree bark, in order for it to work correctly.
Baking Soda and Water
Another method to help get rid of tree fungus is using a baking soda and water mixture. Baking soda is a great gentle solution that prevent fungus from growing because it acts as an antifungal agent. Keep in mind that this solution will not completely get rid of tree fungus. It will simply act as a preventative to stop fungus from growing. You’ll need to use another method to get rid of the existing fungus. Here’s how you can create your own baking soda and water spray:
- Grab pure baking soda at a local convenience store and one-gallon container of water.
- Grab a sprayable container to hold your baking soda and water mixture.
- Pour your water into the container and add one tablespoon of pure baking soda.
- Add one half teaspoon of plain dish soap.
- Shake your container thoroughly to mix everything together.
Now that you have your baking soda mixture, water your trees and shrubs and then wait 2-3 days before applying your baking soda mixture. It’s important to not apply the solution when the fungus is fully exposed to the sun. Spray down the infected area as well as around the tree for best results.
Bleach and Water
The third method to get rid of tree fungus is using a bleach solution. Bleach inherits similar components to chemical fumigants which will help kill and prevent the spread of fungi on your trees and shrubs. Follow these steps to create your own bleach solution for tree fungus:
- Grab 1 cup of Clorox bleach and one quart of water.
- Grab a sprayable container to hold your bleach and water mixture.
- Pour your water into the container and add one cup of Clorox beach.
- Thoroughly mix your solution by shaking the container or using a long spoon.
Like method two of this guide, water your trees and shrubs and then wait 2-3 days before applying your bleach solution. Apply the solution to the affected areas when they are not fully exposed to the sun. Apply the solution two to three times a day until the fungus gets killed off.
Note that very young or small trees might be more sensitive to strong chemicals like bleach. Consider using the baking soda method instead.
Remove Affected Limbs
Another method to get rid of tree fungus is removing the limbs using a bleach and water solution. To use this solution, create the solution from method three. Simply grab one cup of Clorox bleach and one quart of water, and then mix them well.
This time, don’t use a sprayable container as you’ll actually be using a saw or a similar cutting tool to remove the infected limbs. Grab a container and pour your bleach solution inside. Now, submerge your cutting tool for at least five minutes and then rinse it off with clean water.
Carefully cut off the limbs of your tree that are affected with fungi and place them into a disposable bin or container. Keep the fungi away from any healthy trees, shrugs, or other plants. If the fungus is growing near the trunk of the tree, you’ll have to cut into it. Cut it deep enough so that you remove the fungus inside.
After cutting off the limbs, use the Clorox bleach solution or another preventative solution. This will prevent the fungus from growing, and ultimately killing off the remaining fungi. Thoroughly rinse your cutting tool with soap and water as it may be exposed to disease, bacteria, and parasites.
Neem oil is a natural oil that has many uses. A natural insecticide, it will help eliminate the bugs that might be creating or spreading the fungus on your tree or shrub.
Much like fungicides, you can apply it directly to the tree’s bark. It works much like horticulture oil, covering up the spores that create new fungus, before it can spread. It is easier to apply before a tree has leaves, if you are lucky enough to catch it early.
Use these methods to successfully get rid of tree fungus and prevent it from growing. Having healthy trees and shrugs grow is incredibly valuable and great for the environment. Always take proper care of them to prevent diseases and infestations from growing!