Trees are nature’s multitaskers. They provide shade, improve air quality, manage stormwater, boost your home’s curb appeal, and increase property values. But like all living things, trees are also vulnerable to disease, and without the right attention, an unhealthy tree can quickly begin to decline.
Spotting problems before fall is one of the best things you can do to protect your property’s beautiful trees (and your property itself). But as Nashville’s seasons change from summer to fall, it becomes more difficult to tell the difference between a healthy tree going dormant and a sick tree in decline.
Early detection of unusual spots, curling leaves, or dieback gives you a head start on managing any problems and, if needed, treatment for them, to prevent costly removals and keep your yard safe and resplendent.
If you’re concerned about a particular issue with one of the trees on your property, the skilled arborists at The Parke Company are here to help. We’ll guide you in differentiating between concerning issues and natural tree cycles, and will ensure your trees are ready for the winter months ahead.
Tree Disease Control, Nashville, TN
You may already know that tree decay can weaken a trunk or limb, making it more likely to snap during a storm. But there’s more than just broken branches to watch for when you’re monitoring your trees’ health, along with steps you can take to keep your trees in tip-top shape. Here’s what to watch for:
- Weak or damaged branches: Look for dead, decaying, or broken branches, especially ones near your home or power lines. Be sure to have troublesome areas pruned by a skilled arborist.
- Damaged or crumbling bark: The bark on your trees should always be strong and healthy-looking, not brittle or crumbling. These cues can indicate the presence of mold, moss, or fungi, which are usually caused by underlying issues.
- Poor tree structure: A healthy tree has a strong trunk. Trees that split into multiple trunks higher up can indicate weaknesses that are prone to damage from severe weather.
- Pest infestation and disease: Take time to inspect your trees for signs of insects, larvae, and disease. The first signs of infestation or disease include unusual growths and discolored foliage. Identifying and treating these things early can stop them from spreading to other trees.
Fall is a critical time for trees to prepare for winter dormancy. Schedule key treatments like fertilizing, mulching, and strategic pruning to protect against the cold and promote healthy root development.
Five Tree Diseases Nashville Property Owners Should Watch For
Knowing what tree disease looks like will help you act before it’s too late. Here are five of the most common and concerning tree diseases present in Nashville, and tips on how to treat tree disease:
1. Emerald Ash Borer (EAB)
Emerald Ash Borer is technically an insect—an invasive metallic-green beetle that acts like a disease. It hollows out ash trees from the inside, blocking their capacity to transport water and nutrients. EAB was detected in Davidson County in 2014 and led to the decline and death of nearly all untreated trees in the area. It has since become a major problem for ash trees in Nashville, so it’s important to watch for signs of infestation and contact your arborist to discuss treatment options if you’re concerned. Once EAB sets in, decline is rapid, and removal often becomes the only option.
What to look for to recognize EAB:
- D-shaped exit holes in the bark left by emerging larvae.
- A thinning crown or dead upper branches.
- “Blonding” on bark from woodpeckers aggressively digging out larvae.
- Unusual yellow or brown colored leaves falling off earlier than normal.
- Shoots sprouting low on the trunk (epicormic shoots)—a stress response from an infested tree producing leafy sprouts below where the larvae are feeding.
2. Oak Decline
Oaks are iconic in Tennessee, but they’re not invincible. Oak decline is not caused by a single agent but is a “disease complex” condition. It is triggered by multiple interacting stressors (such as prolonged drought) that make it vulnerable to root decay from a variety of fungi, mold, and insects. Trees that are 70 to 90 years of age or older are the most susceptible. Once large branches start to fail, the tree becomes hazardous, so preventive care and stress reduction are crucial.
What to look for to spot oak decline:
- Sparse foliage and small, yellowed leaves.
- Thinning in the upper canopy
- Epicormic sprouts from the trunk and large branches.
- Premature fall coloration.
- Reduced diameter growth – a key primary indicator of oak decline.
3. Anthracnose
This fungal disease is a common concern in Nashville, particularly during cool, wet spring weather. It is known to impact dogwoods and sycamores primarily, but other susceptible species include white oak, ash, maple, and sometimes walnut, hickory, and birch. Fortunately, you can take steps to minimize the impact of anthracnose on your trees. Raking and destroying infected leaves and twigs in fall and pruning sycamores can eliminate fungus from overwintering, while proper water and fertilization help trees better withstand infections.
When checking for anthracnose, look for:
- Tan, brown or reddish-brown blotches or spots on leaves, often along the veins.
- Cupped or curled leaves.
- Premature leaf drop.
- A progressive scorched appearance on the leaves.
- Twig dieback.
- Sunken areas with swollen edges, known as ‘cankers.’
- Gnarled or crooked branch growth and side shoots.
4. Oak Wilt
Unlike oak decline, oak wilt is a fast-acting, fatal disease that begins with rapid bronzing and the dropping of leaves, starting at the crown. One of the most dangerous fungal threats to oaks, it spreads underground through root grafts and overland via beetles, and can kill a tree within a season. In red oaks, which are highly susceptible, symptoms can lead to death in weeks, while white oaks will exhibit slower wilting.
If you suspect oak wilt, it’s important to contact an arborist or the Tennessee Department of Agriculture for a conclusive diagnosis. Because oak wilt spreads so easily, quick detection and professional management are critical.
How to identify oak wilt:
- Cracks in the bark or a sweet-smelling fungus beneath the bark.
- Brown discoloration starting at the leaf tips and moving inward.
- Rapid leaf curling and premature dropping.
- “Flagging,” a term that describes branches with dead and dying leaves.
- Sprouts or suckers that appear at the base of the tree.
- White, gray, or black fungus underneath the bark.
5. Verticillium Wilt
This disease is caused by a soil-borne fungus (primarily Verticillium dahliae in the Southeast) that clogs the tree’s water-conducting tissues. Symptoms are most visible during the hot, dry summer weather. This fungus can kill a tree and can persist in the soil for years, making prevention and management critical. Susceptible trees include the maple, redbud, ash, magnolia, tulip tree, elm, and catalpa.
Regular monitoring and soil management help protect particularly vulnerable species.
To identify verticillium wilt, look for the following signs:
- Yellowing or wilting leaves on scattered branches, often starting on one side of the tree or on a single branch
- Streaking in the sapwood (vascular discoloration)
- Branch dieback
- Stunted growth
- A gradual decline in resilience
How to Prevent Tree Disease
Now that we’ve introduced the most concerning and pervasive tree diseases, the next step is learning how to detect tree disease to prevent it from worsening or causing damage. Late summer and early fall are ideal times to conduct a little due diligence, because symptoms are still visible before seasonal color changes mask them. Here are some simple but important checks you can make to catch problems early:
- Walk your property: Take a slow lap around your yard, looking up into the canopy for thinning crowns, dead tips, or unusual color changes.
- Check the bark: Look for cracks, exit holes, peeling bark, or fungal growths.
- Inspect the leaves: Notice whether spots, blotches, or early dropping are limited to one limb or spread across the tree.
- Compare trees: If one oak looks sickly while others look fine, that’s a red flag.
- Keep notes: Snap photos or jot down what you see. This helps a professional arborist diagnose the issue faster.
What to Do if You Spot Tree Disease Symptoms
If you suspect tree disease, don’t ignore it. Start by documenting what you see through photos of the leaves, bark, or thinning canopy. This will help your arborist make a faster and more accurate diagnosis of the problem. Resist the urge to try DIY fixes because most tree diseases require precise techniques and specialized equipment for effective treatment. It’s always best to call a certified arborist who can confirm the problem and then recommend the right treatment or safely remove a hazardous tree if necessary. Above all, act quickly; the longer you wait, the greater the risk of the disease spreading.
Prevention Is Always Better
As we always say, preventing tree disease is far better than facing the expense and heartache of losing a beloved tree or risking harm to your people or property. Simple habits like mulching properly, watering during drought, and avoiding root compaction can go a long way in keeping your trees healthy. And when problems do arise, early action makes all the difference.
You will never regret being proactive with tree maintenance on your property. Contact our local experts at The Parke Company for help keeping your beautiful trees healthy and thriving year after year.