Why Tree and Shrub Care is So Vital to the Health of Your Plants

Posted on January 10, 2022

The trees and shrubs on your Tennessee property are a valuable part of your landscape and important enough to protect. Not only are they an attractive element to your lawn, but they also lower energy costs, provide shade, act as sound and pollution barriers, and increase the value of your home. Unfortunately, like all living things, there are plenty of potential problems that could be causing your trees and shrubs harm. One likely culprit is tree pests such as mites and insects. Various tree insects thrive here in Knoxville, waiting to wreak havoc on your beloved lawn ornaments. Emerald Island has listed the most common tree pests, the damage they inflict on your Tennessee trees and shrubs, and how you can prevent and stop these pesky bugs from causing damage.

Scale Insects

These sap-loving insects love to use their piercing mouthparts to suck the sap out of your trees and shrubs. There are two different kinds of scale insects, the soft and the armored scale, which can be found on branches, stems, foliage, or fruit. Armored scales are covered with a clear wax shell. Winged males crawl out from beneath their cover and mate with covered females who produce eggs.

Soft scales do not have a shell. Instead, they protect themselves through a sticky substance called honeydew. This shiny and wet substance causes the growth of a black fungus. Not only does it attract ants, flies, wasps, and other pesky insects, it causes yellow and wilting of the leaves, stunts growth, can cause early defoliation and even death.

You can help prevent scale by using a routine plant health care program and the use of horticultural oil, a unique blend of natural oils that suffocates overwintering insects such as scale when used correctly.

Spider Mites

Spider mites resemble a spider but are so small they are hard to see with the naked eye. They are members of the arachnid class, along with spiders and ticks. Spider mites feed on the chlorophyll of your plants, including boxwoods, arborvitaes, burning bushes, and spruce trees. A small number of spider mites isn’t usually a cause for concern, but a large infestation can be detrimental. The damage they cause appears as yellow or brown patches on the leaves. You may also notice as these pests continue to feed, the plant’s health will continue to deteriorate, and the damaged foliage will fall off.

It’s important to keep your Knoxville tree and shrubs hydrated because water-stressed plants are more likely to be damaged. Spider mites have many natural enemies that often limit populations. Spraying chemical insecticides may actually do more damage by killing the beneficial insects that prey on them. Therefore, it’s best to call in a professional who understands and knows how to treat specific tree ailments.


Like scale insects, aphids also create honeydew. They, too, use their piercing mouths to suck the sap out of your trees. They can become a huge pest quickly due to their rapid reproduction rate. Like scale insects, the honeydew they produce not only attracts other flies, wasps, and ants, the substance itself can cause the plant to wilt, yellow, or die. 

A small number of colonies can be crushed by hand or removed by pruning. A large infestation may need to be treated with insecticides. Horticultural oil applied in late fall or early spring can help protect and prevent overwintering insects by suffocating them out.

Leaf Miners

While there are several kinds of leaf miners here in Knoxville, a large majority of them are the tiny black flies. It is not the flies that cause the damage but the larvae. After the female lays eggs in the leaves of plants, the larvae cause damage by tunneling through the leaf tissue. As the larvae feed on the leaf tissue, it dies and leaves behind what appears like yellow squiggly lines on the leaves. 

The best way to eliminate leaf miners is through pesticides, but they must be sprayed at the right time. If you spray too early or too late, the pesticide will not reach the leaf miner larva and kill the flies. Another way of ridding your landscape of leaf miners is through neem oil. This natural insecticidal oil impacts the leaf miner’s life cycle reducing the number of larvae that become adults.


This pest gets its name from the bag it creates with silk and pieces of your plant’s foliage. Female bagworms live their entire life inside their bags until they breed. The eggs emerge in the spring, create their own bag, and use it to travel from tree to tree. So why are these tiny caterpillars so damaging? Bagworms chew small holes in the leaves on deciduous trees, causing defoliation. On evergreens, they feed on the buds and the foliage causing the branch tips to turn brown and die, leaving the tree unable to photosynthesize and make food to survive.

Bagworms can be difficult to control because they often go unnoticed until you see the bags. Although time-consuming, you can handpick each bagworm and destroy them. Bacillus thuringiensis can be used when the bagworms are small, but timing is everything. Again, it may be best to call in a professional.

Japanese Beetles

Japanese beetles are invasive species that feed on the leaves, flowers, and fruit of more than 300 species of plants. It is a caterpillar-looking creature that feeds on the blades of your grass, causing it to turn brown and die. These unfathomable creatures skeletonize leaves by feeding on the tissue between your tree’s major veins. The damaged leaves turn brown and fall off. Vulnerable plants such as those already injured or not yet mature may suffer enough damage to die.

With Japanese beetles, timing is everything. Maintaining healthy trees and shrubs through a tree and shrub care program that includes fertilization and insect control will go a long way toward protecting your plants.

When small numbers of Japanese beetles are involved, physically removing them can be effective. Handpick or knock them into a bucket of soapy water. Several different kinds of insecticides have proven to be somewhat effective, including products containing pyrethrins (e.g., Pyola®) or neem oil. Still, they must be repeated every several days and are only effective if small numbers of Japanese beetles are involved. Like with the other insects, calling in the professionals is still probably your best bet.

Protect Your Trees and Shrubs Now With Tree and Shrub Care Service From Emerald Island Lawn Service

At Emerald Island Lawn Service, our full-time, dedicated, and highly-trained horticultural specialists have the knowledge and experience to take care of your prized trees and shrubs. We know what trees and shrubs are local to the Knoxville area, the pests that threaten them, and how to best prevent and treat them.

For the best protection of your trees and shrubs, invest in Emerald Island’s tree and shrub care service. With custom-blended fertilizers, horticultural treatments, and regular monitoring, inspection, and evaluation of your beautiful plants, our tree, and shrub care service will improve the health and vigor of your trees, shrubs, and entire landscape.

Learn more about our tree and shrub care service by contacting us now. Feel free to contact us via our easy-to-use online contact form or by giving us a call at 865-588-4497.

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