Tree Disease & Pest Treatment in Knoxville, TN

Common tree problems around Knoxville

Two invasive insects cause the most worry here. The emerald ash borer kills ash trees by tunneling under the bark, and it is now found throughout Knox County. The hemlock woolly adelgid shows up as small white cottony tufts on the undersides of hemlock needles. It has killed many hemlocks in the Smokies and is common on landscape hemlocks across the region.

Fungal diseases are also common in the humid valley. Hypoxylon canker shows up on drought-stressed oaks after a dry summer. Root rots develop in poorly drained clay. Anthracnose spots the leaves of dogwoods and sycamores during wet springs.

Treatment options

Many insect problems can be managed if they are caught early. High-value ash trees can often be protected with trunk injections every year or two. Hemlocks can be treated with systemic products applied to the soil or trunk, which can protect them for several years. These treatments must be applied by a licensed pesticide applicator, which is part of why it is worth hiring a professional.

For fungal problems, the most effective step is often improving the tree's growing conditions. That can mean mulching instead of mowing over the roots, watering deeply during dry spells, pruning out infected limbs in the dormant season, and avoiding soil compaction from vehicles and construction.

When treatment is not worth it

A good tree professional will tell you honestly when a tree is too far gone. An ash that has already lost more than about half its canopy rarely recovers. A trunk with extensive internal decay may be a falling hazard no matter how green the leaves look. In those cases, planned removal is safer and usually costs less than an emergency call after it fails.

If you remove a diseased tree, think about replacing it with a different species. Native options that do well in Knoxville include red maple, blackgum, white oak, and serviceberry for smaller yards.

Signs your tree needs a professional look

Call for an inspection if you notice leaves wilting or browning in midsummer on only part of the tree, bark falling off in sheets, new holes or sawdust at the trunk, or branches dying back from the tips. Sudden thinning of the crown over one or two seasons is another warning sign, especially on ash and hemlock. Early diagnosis keeps more options open, and it often costs far less than removing a large dead tree later.