Will Your Oak Tree Survive Severe Weather?

Oak trees are a staple across the United States, offering shade, beauty, and supporting the ecology of many residential landscapes. As a homeowner, they'll also add value to your property if they're healthy and well-maintained. Learn how to ward off common diseases, protect their root systems, and improve their canopy to ensure that your majestic trees remain healthy — and importantly, strong enough to endure severe weather.

Common Oak Tree Diseases

Oak trees are susceptible to various diseases that can compromise their health. If you notice changes in the green foliage on an otherwise healthy tree, consider the following:

• Oak Wilt Disease: This fungal disease spreads through root grafts and insect vectors, causing leaf discoloration, wilting, and eventually death.
• Anthracnose: A fungal disease that causes dark, sunken lesions on green leaves, leading to premature leaf drop on infected trees.
• Powdery Mildew: This fungal growth appears as a white, powdery coating on leaves. Over time, it can stunt healthy growth and reduce the tree’s vigor.

Pest Infestations

Several common pests can affect mature oak trees, weakening them and making them more susceptible to potential foliage loss and disease:

• Oak Leaf Roller: These caterpillars feed on oak leaves, causing significant defoliation.
• Two-lined Chestnut Borer: This beetle's larvae tunnel through the tree’s bark, disrupting its well-balanced nutrition.
• Spongy moth (formerly known as Gypsy Moth): The larvae of this invasive species consume large quantities of leaves, which can defoliate and stress the tree. Don't believe me? Our trees were bare during a summertime infestation, and we lost several larger branches that couldn't sustain the damage from these natural predators.

Proper Soil and Water Management

Tree experts cite that healthy soil and adequate water are essential for oak tree health:

• Soil Quality: Oak trees can survive in a range of soil conditions, but they'll thrive if the soil is well-drained and rich in organic matter. Soil compaction can hinder root growth and water absorption.
• Watering: Young oak trees need regular watering, especially during dry periods. Mature oaks require less frequent watering but should be watered deeply to encourage strong root systems.

Note: Mulching around the base of the tree can help retain soil moisture and regulate the soil temperature.

Pruning and Regular Maintenance

Proper pruning and maintenance practices help promote overall oak tree health:

• Tree pruning: Remove dead, broken, or diseased branches can help prevent the spread of infection, improve air circulation, and create a healthier tree canopy. Pruning during the dormant season (the winter months) can minimize undue stress and the risk of disease spread. Avoid excessive pruning, and consult with a professional arborist for branches overhanging structures.
• Maintenance: Regularly inspect the tree for signs of storm damage or disease. Avoid injuring the tree trunk and roots with lawn equipment.

Tell-Tale Signs Your Tree Might Not be Strong Enough to Weather a Storm

"Trees can fail in various ways if not properly maintained, starting at the roots. Strong winds and saturated soil from hurricanes can cause tree roots to become uplifted, which can be extremely dangerous to your home," warns Blake Watkins, Certified Master Arborist and Operations Partner at Monster Tree Service. "Keep a close eye on the trunk and base of your tree, as decay in this area can cause mature tree failure. Sloughing bark, open cavities, hollow sections, and fungal fruiting bodies can all be signs of trunk decay. These can all be signs that your tree is too weak for a strong storm (like a hurricane). Watch for a lifting root plate rising on one side and sinking on the other as well, as this can be a sign that your tree won’t survive through a storm. If you see this, call an arborist immediately."

Additionally, pay attention to the branches. "You may notice a weak point on your tree where a trunk splits into multiple codominant stems. That area can contain bark and may be a site of decay, making them more susceptible to splitting. An arborist can help you determine if this can be mitigated by pruning or cabling."