Common Tree Fungi and How to Spot and Prevent Them

Trees can be susceptible to a range of diseases, especially fungal infections. Fungi thrive in moisture-rich environments, and once they infect a tree, they can cause serious damage, potentially leading to tree death. Understanding the types of harmful fungi, how trees get infected, and what you can do to protect your trees is essential for maintaining their health and longevity.

What are Some Bad Types of Tree Fungi?

There are many types of fungi that attack trees, but some of the most harmful are as follows:

1. Armillaria Root Rot: This aggressive fungus attacks the roots and lower trunk, weakening and killing the tree. It is particularly dangerous because it spreads underground to infect nearby trees.
2. Oak Wilt: This is a fungal disease that affects oak trees. It disrupts the trees’ ability to transport water and nutrients. It often results in rapid leaf discoloration and wilting, leading to tree death if untreated.
3. Anthracnose: Affecting multiple varieties of trees, including sycamore, ash, and dogwood, anthracnose causes dark, sunken wounds on leaves, stems, and fruit. It weakens the tree, making it more vulnerable to other diseases.
4. Powdery Mildew: This common fungal disease appears as a white, powdery coating on the leaves. While it is not usually fatal, it weakens the tree by reducing photosynthesis, which can lead to other problems over time.

How Do Trees Get Fungus?

Trees can contract fungi through several pathways, but the most common causes include:

• Moisture and Humidity: Fungi thrive in damp environments, so trees in areas with high humidity or standing water are more prone to infection.
• Wounded or Stressed Trees: Open wounds from pruning, storm damage, or other stresses provide an easy access point for fungal spores to invade the tree. This is why storm damage tree cleanup after a weather event is crucial! 
• Contaminated Soil or Tools: Some fungal diseases, such as root rot, can spread through soil, while others can be introduced through contaminated pruning tools.

What are the Signs of Tree Fungal Disease?

Early detection is crucial to saving a tree from fungal disease. Key signs to watch for include:

• Discolored Leaves: Yellowing, browning, or wilting leaves can indicate a fungal infection if the pattern seems unusual or affects the entire tree.
• Unusual Growths: Fungal fruiting bodies, such as mushrooms or conks, growing on tree bark or roots are often a sign of internal decay.
• Bark Damage: Peeling bark, cankers, or oozing sap may indicate a fungal infection.
• Stunted Growth: If a tree’s growth has slowed significantly or branches are dying, it could be due to an underlying fungal issue.

What Can I Do if My Tree Has a Harmful Fungus?

If you suspect your tree has a fungal infection, immediate action is necessary as follows:

1. Prune Infected Areas: Remove any affected branches or leaves, sterilizing pruning tools between cuts to prevent fungus spread.
2. Improve Air Circulation: Thinning the tree’s canopy or reducing nearby vegetation can lower humidity levels, making it difficult for fungi to thrive.
3. Consult a tree care professional: Some fungal infections like oak wilt or root rot may require professional treatment, such as fungicide applications or soil amendments, to save the tree.

An Ounce of Prevention is Worth a Pound of Cure

Preventing fungal diseases is easier than treating them once they occur. Here are some preventative steps you can take:

• Water Wisely: Overwatering creates conditions ideal for fungi. Ensure proper drainage around your trees and avoid watering the leaves or trunk directly.
• Proper Pruning: Prune during dry weather and avoid leaving open wounds that invite fungal spores.
• Mulch and Fertilize: Mulch around your tree’s base to retain moisture and regulate soil temperature. Proper fertilization ensures your tree has the nutrients it needs to stay healthy and resistant to disease.

Protect Your Trees with Expert Care

Fungal diseases can severely impact your trees’ health and longevity if not properly managed. While recognizing early signs and taking preventative measures are essential first steps, professional expertise can make all the difference in protecting your valuable landscape investment. That’s where Valley Arbor Care comes in. Our professional arborists bring decades of experience in treating and preventing tree diseases throughout the region, as well as storm damage tree cleanup. Whether you need routine maintenance, disease treatment, or a comprehensive health assessment, we provide the expert care your trees deserve. Contact Valley Arbor Care today to schedule a consultation and give your trees the professional attention they need to thrive for generations to come.