Last Updated on March, 2025
Have you noticed those weird growths or mushrooms on trees while wandering in your garden? It turns out those could be fungi, but how can you tell if what you’re looking at is a tree-friendly fungus or something else entirely?
Fungus identification is not rocket science, but it does take a keen eye and a bit of know-how.
That’s where this article comes in.
In this article, you’ll find the most common types of tree fungi, the characteristic features of their mushrooms, and how to treat them. If you’re ready, let’s get started.
Quick Summary
- Tree fungi can be identified through signs like soft spots on the trunk, unhealed wounds, spots on leaves or branches, and mushroom growth. Observing the fungi’s color, shape, and texture is essential for proper identification.
- Tree fungi can weaken and kill trees by consuming nutrients, causing diseases such as root rot, anthracnose, and oak wilt. Some fungi like wood decay fungi play a beneficial role in forests by decomposing dead wood, but they are harmful in gardens.
- Early detection and professional treatment are crucial to managing fungal infections. Fungicide application, good irrigation practices, and proper pruning are recommended. For severe infections, removing infected trees might be necessary to prevent the spread to healthy ones.
Identifying Tree Fungus: Some Common Methods
Below are some simple ways to identify a tree fungus.
Soft Spots On Trees
Soft spots on trees occur due to fungal infections, extra moisture, or other damage to the tree. Most tree owners don’t notice soft spots because they don’t touch the trees.
Run your hands through the tree bark and see if you notice any soft spots. It’s recommended that you do this twice a year.
Usually, fungus infects trees in early spring or summer, but the symptoms will start to appear in the winter or late spring. So, if any part of the bark doesn’t feel right, you must contact a professional right away and determine the reason.
Remember you have waited a season already, and it’s better to treat it as soon as possible.
If soft spots are due to moisture, plant trees that absorb moisture or trees that are suitable for a wet climate.
Unhealed Wounds
Did you know that, like humans, your trees get wounded too? When you or any other animal makes a cut on a tree, it gets damaged. Then, the healing process starts, and a scab or covering forms on the wound.
That’s where the wood decay fungi come in. Trees require a lot of nutrients and water to form this covering. Hence, they flood the wounded area. Fungus invade this space and feed on these nutrients.
The result is that fungus consumes all the nutrients meant for the tree, and the tree gets weakened and eventually dies.
So, if you notice that the wounds on trees have not healed for a long time, you must call a professional.
Fact: Wood decay fungi feed on dead trees and release nutrients to the soil. This process is useful in the forest ecosystem but not in your garden.
Spots On Leaves and Branches
You might often notice spots on leaves and branches. These can be due to fungi or bacteria.
Some are not dangerous, and some could decay and kill your tree over time. If you notice any spots on leaves or branches, observe them well.
If they appear darker, the situation could get worse. You must call a professional to identify the exact reason for the spots and treat it accordingly.
Mushroom Growth
Mushrooms are the upper part of the fungi. They might be beautiful, but they feed on the tree’s nutrients and can decay and kill your tree over time.
If you notice large or small clusters of mushrooms near your tree, call a professional for identification. Don’t remove all the mushrooms by yourself, as it is better for a professional to see it first.
Most Common Types of Tree Fungus and Their Identification
The fungus has two main parts: the fruiting body and the mycelium. The fruiting body is the visible part, and the mycelium is present within the soil to absorb nutrients for growth.
To identify the type of tree fungi, you must look at the colour, shape, and texture of the fruiting body.
Let’s look at some of the common tree fungi and the way to identify them.
Turkey Tail Fungus (Trametes Versicolor)
The Turkey Tail is a shelf fungus, which means it looks like little shelves protruding from the tree trunk. The distinct feature of this fungus is its psychedelic colour.
It’s velvety at the upper part and creamy at the bottom. In between, you’ll notice concentric striations in different shades.
You can find Turkey Tail fungus on cut wood, fallen wood, and wounded areas of a tree. It turns the wood white and spongy initially and gradually causes it to rot and die. The size is around 1-4 inches across.
Chicken of the Woods (Laetiporus Sulphureus)
Chicken of the woods is another common type of tree fungus in the UK. It’s bright yellow with thick, lumpy brackets. The upper part has an orange shade.
Chicken of the Woods fungi are mainly found on the trunks of yew and oak trees, but they may also be present in deciduous tree trunks. The size is around 40 cm across.
Artist’s Conk (Ganoderma Applanatum)
Artist’s Conk is another tree fungus that has overlapping groups of conks. The top part is brown, and the bottom appears white.
These fungi cause sap rot and heart rot in roots and trunks. Furthermore, it decays some trees at the base, which is known as butt rot.
If you draw something on the underside or scratch it, the pattern will turn dark.
Oak Mazegill (Daedalea Quercina)
Oak Mazegill is a tree fungus that’s widespread in the UK. It has a woody bracket and is shaped like an upside-down cone.
The undersurface has a network of fissures, but the upper surface is plain with greyish-brown colour.
Oak Mazegill grows on the dead wood of oak trees and sweet chestnuts. It is about 20 cm across.
Tip: You might confuse Oak Mazegill with other varieties, such as Birch and Conifer, but remember that, as the name indicates, Birch and Conifer Mazegill grow mostly on birch and conifer trees.
Oyster Mushrooms (Pleurotus Ostreatus)
Oyster mushrooms can be found as clusters forming a shelf-like arrangement. The upper surface is smooth and creamy in colour while the lower surface has characteristic gills that extend downwards toward the stalk.
They grow on tree trunks and decay the heartwood and sapwood, resulting in a white, flaky rot.
The rot is localised, usually 10 feet in either direction of the mushroom. Acacias, beeches, magnolias, olives, oaks, and other trees are some of the varieties susceptible to this fungus.
Wood Ear (Auricularia Auricula-Judae)
Wood ear is a jelly fungus with a gelatinous, coppery red appearance. You are most likely to find this in colder months on dead or dying branches or fallen branches on the forest floor.
They’ll grow in shelf-like clusters. Some people consume this mushroom as it’s delicious.
Warning: Don’t eat random mushrooms without confirmation from an experienced mushroom forger. Many mushrooms can be poisonous or deadly if you identify them incorrectly.
Southern Bracket (Ganoderma Australe)
The southern bracket has a thick, woody, semi-circular, large bracket that grows on dead and living trees.
It mainly grows on beech trees but can be found on other deciduous trees as well.
The upper surface is dark brown or reddish, and the lower surface is cream-coloured. The lower surface resembles a canvas, which means you can draw clearly visible patterns on it.
Fungal Diseases and Treatments
All fungi are not fatal, and they don’t attack all tree species. However, certain tree species are susceptible to specific tree fungi that cause disease.
You must understand the diseases and their symptoms to treat them before the situation gets severe.
Below are some common diseases caused by tree fungi, their symptoms, and treatments.
Armillaria Root Rot
Armillaria root rot is also known as oak root fungus. However, it affects many species of tree other than oak.
Different species of fungi are responsible for root rot, including Armillaria and Phytophthora. Root rot can kill the tree. Below are some of the common signs of armillaria root rot:
- Appearance of mushrooms.
- Wilting leaves.
- Leaves turn yellow or brown.
- Stunted growth.
- Leaf drop.
Here are some methods to prevent root rot disease:
- Don’t spray water directly onto the trunk or foliage.
- Keep irrigation at ground level.
- Don’t overwater the trees.
- Plant water-loving trees to absorb extra water on the ground.
Anthracnose
Anthracnose is a foliar disease that appears in the spring season. However, the disease is harboured in the winter.
The symptoms include the appearance of brown/tan spots surrounded by purplish rings, blotches, and wilting leaves. Brown spots may also appear on berries.
Infected trees will eventually die. To prevent this, you must rake up the leaves left around the trees after winter.
Shot Hole Fungus
When your tree is infected by shot hole fungus, you may notice imperfections and holes initially.
You might mistake this for insect damage, but after some days, reddish-brown spots will appear. By mid-summer, the leaves will turn yellow and drop.
This fungal disease stresses your tree, making it vulnerable to insects and other plant pathogens. To prevent this from becoming severe, you must spray fungicide when you notice the initial symptoms.
Dutch Elm Disease
Dutch elm is a fatal disease that affects the tree’s conductive tissues. When the vascular system is weakened, the tree can’t properly circulate nutrients and water. Signs of Dutch elm include leaf curling, wilting, and dropping.
You can grow resistant cultivars to control this disease. Controlling bark beetle infestations, who spread this fungus, is also a way to prevent it.
Powdery Mildew
Powdery mildew is one of the easily recognizable fungal diseases. These fungi attack the plant leaves directly, resulting in white powder dusting on the foliage.
This disease is not fatal, but the aesthetic look of the plant is spoiled till the infected leaf drops.
To prevent the spread of this fungal disease, you must place the plants at a certain distance to promote air circulation and practise good irrigation policies.
Additionally, sulphur-based fungicides should be used and you should prune the infected leaves.
Cercospora Leaf Spot
Cercospora leaf spot is a type of foliar disease. If a tree is infected, you can notice leaves with brown spots surrounded by tan blotches.
Over time, the number of spots will increase, and the tree won’t be able to carry out photosynthesis, and tree health will be affected.
Crepe myrtle is one of the main trees infected by this tree fungus.
Several types of fungicides are available on the market to control this. You can use one of those to treat it.
Oak Wilt
Oak wilt is a fatal disease that affects all oaks, but mainly the red oak. Infected trees will show the following symptoms:
- Wilting of leaves.
- Leaf drop.
- Browning of leaves out of season, such as in the spring or early summer.
This fungus spreads through the intertwined root systems. Hence, you must remove the infected tree as soon as possible to prevent it from spreading to the other oaks nearby.
Seal the pruning cuts and keep sap beetles away from the trees.
Sooty Mould
Sooty mould is a foliar disease, and infected trees will have leaves that are covered by a black film. This fungus blocks the plant from receiving sunlight and stunts its growth.
It’s spread by insects and affects trees like silver maple, linden, elm, etc.
Sooty mould is not fatal; however, you can prevent it by spraying the plant with neem oil or water to get rid of insects.
How Do Trees Get Fungus?
Trees get fungus in several different ways. Fungi are mainly spread through spores. These spores travel between trees in different ways such as insects, wind, birds, furry animals, and root-to-root contact.
Sometimes, spores splash from the soil onto the tree trunk due to heavy rain. Improper irrigation and infected gardening tools can also lead to fungus growth. The fungus can also spread to trees from your own body.
While some infection methods can be controlled, others are out of your control. Hence, early detection of symptoms and treating the tree is essential.
When a fungus attacks plants, the host tree has a mechanism to fight it back. However, the tree’s fighting mechanism weakens if it has cuts, wounds, damaged roots, branches, etc. In this case, the fungus can invade and damage the tree easily.
How to Get Rid of Tree Fungus?
Many species of wild mushrooms can grow on your landscape trees and damage them. Hence, fungus identification is the first step in treating fungal infections.
If you notice the below signs a fungus might have infected your tree:
- Visible fungus growth.
- Leaf discolouration.
- Wilted leaves.
- Soft spots on the tree trunk.
- Wood particles around the trunk.
If you notice one or more of the above signs, call an arborist immediately. They will recommend a treatment. The most common treatments are comprehensive tree care, tea trimming, and spraying fungicides.
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Final Words
Most fungi grow on dead and living trees, causing them to decay over time. Soft spots on the tree trunk, unhealed wounds, spots on leaves and branches, and visible mushrooms are some of the common signs of tree fungi infection.
The fungus can cause butt rot and sap rot in hardwood trees and cause them to die eventually. Usually, they spread by spores, and the first step in treating it is fungus identification, which can be done by observing the mushroom’s colour, shape, and texture.
You must call an arborist to confirm the fungal type and treat your tree effectively.
