You have tree bugs. We can help. In our language, it’s called “plant health care.” Some of you may be thinking, “I vaguely remember learning about trees when I was in the 4-H club, but I’ve never heard of plant health care before.” Others may be asking, “Wait, are you suggesting there is something I could have done to prevent these bugs from getting in my trees?” Or perhaps you’re echoing our favorite refrain, “I still have no desire to know anything about plant health care. That’s why I have you.”
No matter what situation you’re in, we’re glad to help.
Most folks don’t call our office or visit our website looking specifically for plant health care specialists. They search for things like, “what are these white bugs on my trees” or “signs that my trees are dying,” and they stumble upon the fact that they may be in need of a plant health care expert. So let’s start with a simple definition of plant health care.
If you grew up around trees, you may know a thing or two about them. But taking care of trees, and ensuring their health and longevity, can be complex.
There is a right and a wrong way to trim a branch to ensure the health of the tree. There are suitable planting sites and recommended planting practices. There are environmental conditions that can impact the condition of your trees, including extreme weather, disease and infestation, soil chemistry, nutrient deficiencies, and much more.
In short, plant health care (PHC) is about managing the health of your shrubs and trees, and the conditions around them, to ensure they’re not vulnerable to disease. Here at Carolina Tree Care, we’re all about preventing, monitoring, diagnosing, and controlling disease in a continuous cycle.
Did you know? Nobody puts crepe myrtle in a corner. No, really. It needs a lot of space to thrive.
There are many trees that are indigenous to the Carolinas, and each species may be susceptible to a different type of pest or disease. Local arborists, like those at Carolina Tree Care, can perform an inventory of your property and identify tree populations that may have specific vulnerabilities. They can then advise you on the recommended treatment protocols and proper timing of those treatments.
Common Trees in North and South Carolina
|Crepe myrtle trees||Japanese beetles and aphids|
|Red maple trees||Gloomy scales|
|Willow trees and water oaks||Lecanium scales|
|Ash trees||Emerald ash borer (EAB)|
|Leland Cypress trees||Bagworms, seiridium canker, and box canker|
|American elm trees||Dutch elm disease|
|Camillia trees||Tea scale and cottony camellia scale|
|Boxwood trees||Leafminer and spider mites|
Did you know? Removing inoculum (pruning diseased branches and raking leaves) from the area should be part of any integrated strategy.
We often hear about invasive pests like the Asian Longhorned Beetle that are native to areas like Eastern China and, once introduced to North America, threaten to destroy our hardwood trees. (Build a wall!) However, most landscape pest issues are due to other fundamental challenges, including soil chemistry and structure, poor planting practices, inappropriate planting sites, mechanical damage such as improper pruning and trimming, or environmental injury (i.e., too hot, too cold, too dry, too wet).
It can be fairly easy to predict a looming pest issue if there’s a growing threat, like the emerald ash borer, which is spreading quickly throughout our country (including the Carolinas). Other issues, such as nutrient deficiencies, compacted soil, pH balance, and more, may not be quite as easy to spot by an untrained eye.
Did you know? Ambrosia beetles are attracted to stressed trees, which introduce the ambrosia fungus that can disrupt the tree’s vascular system. And we thought we were the only ones who were stressed! So much for the health benefits of tree pose.
At Carolina Tree Care, we believe that preventative treatments work best because healthy plants are not only less susceptible to disease, but also less affected should they contract disease. However, we also know that we’re often brought in after a disease or infestation has already presented itself.
The good news is that treatment options are available, depending on the condition and when it was discovered.
What you may not realize is that there’s an art and a science to preventing tree-related diseases. The main question we ask is, “How can we intervene over time to ensure the health of your tree?” but it breaks down into three separate buckets:
To answer these questions, we have a lot of options in our plant health care toolbox — all of which are available to you.
Did you know? Plant health care specialists work with you to set “action thresholds,” which simply means that, depending on the pest, they know when your trees are most susceptible to disease and when to act to ensure damage remains within tolerable levels (i.e., we don’t over- or under-react).
Plant health care treatments are not one-size-fits-all. The following is an abbreviated thesaurus of common treatment options; however, the specific treatment recommended will differ based on a number of factors, such as the type of tree, type of pest, time of year, and stage of disease.
Systemic applications (see systemic bark spray, root flare treatments, and tree injections) are “any applications that utilize the vascular system of a plant for distributing the treatment to other parts of the plant.” These applications are especially useful when other treatments are difficult (e.g., complicated location, challenging height) or when the treatments need to be absorbed by the tree for continued protection from subsequent pest arrivals.
With systemic bark sprays, a PHC professional will spray the trunk of a tree and the treatment will flow through the tree’s vascular system and beyond. Although skeptics remain, statistically significant, head-to-head studies have shown equivalent performance of bark spray versus soil applications and soil-applied treatments. Depending on the pest, bark spray may be used when the pests are dormant followed by a foliar spray during the growing season when the majority of blossoms are open.
Foliar spray allows a PHC professional to apply fertilizer directly to the leaves on a tree, which allows the tree to absorb the product quicker than it may through the roots. Foliar spray is often used to overcome nutrient deficiencies, such as a lack of iron, magnesium, potassium, or calcium, that can lead to leaf discoloration, shortening of shoots, bands along the leaf veins, and more. Contact foliar spray that does not travel throughout the tree may also be used to treat existing pest manifestations.
Soil application allows a PHC professional to apply specific chemicals to the soil at the base of a tree to prevent the growth of targeted organisms or microorganisms.
Soil drenching allows a PHC professional to apply an herbicide or fertilizer directly to the root of a specific tree, typically by digging a trench at the base of the trunk and pouring the chemical onto the exposed soil. Soil drenching works best when the ground is not frozen or saturated with water and often requires additional treatments every three years.
Tree injection or trunk injection allows a PHC professional to inject herbicide directly through the bark of trees, typically when the tree has a full canopy. Tree injections tend to occur early in the growing season after the full leaf is out (and optimally applied prior to the onset of visual symptoms), with annual reapplications.
Tree growth regulators (TGR) allow a PHC professional to release chemicals in small amounts to alter the growth habits of trees. Trees that have been treated with growth regulators are typically greener and healthier looking — and rarely need to be pruned every year. Tree growth regulators may be used to inhibit growth of trees that you would like confined to smaller spaces, including trees that, unfortunately, may have been planted under utility lines.
Eradicative pruning allows a PHC professional to remove infected branches to control tree pests and prevent further spread of their pathogens. Eradicative pruning may be used in urban forests where the general public is requesting decreased chemical use; however, this treatment is tree-specific and does little to stop the spread of disease and pests in the broader ecosystem. A more successful approach would be to couple this with cultural (e.g., well-drained soil, correct mulching) and chemical treatments.
Sanitation pruning allows a PHC professional to control tree pests by destroying the host material where they breed and take refuge over the winter. Sanitation pruning requires not only removing infected branches, but also destroying or disposing of them and raking the leaves from the ground to reduce reproduction sites.
Tree cabling and bracing allows a PHC professional to provide a supplemental tree support system to trees that have structural defects or conditions that pose a high risk of failure.
Did you know? The key is in the timing of the foliar spray. For example, depending on the pest, a plant health care technician may begin to spray in the spring during leaf expansion with continuous leaf moisture for 6+ hours. Retreatment may then be scheduled for 14–21 days later.
At Carolina Tree Care, we understand the Growing Degree Days (GDD) for North and South Carolina. GDD are a measure of heat accumulation used by horticulturists, gardeners, farmers, and talented arborists (yes, us!) to predict plant and animal development rates such as the date that a flower will bloom or a crop will reach maturity — or the date that anticipated pests may arrive.
The GDD calculation is fairly simple: Add the seasonal high temperature and the seasonal low temperature, divide by 2 (to get an average) and subtract 50⁰. If the seasonal high for your area is 70⁰ and the seasonal low is 50⁰, the average seasonal temperature is 60⁰. When you subtract 50⁰, you get a GDD of 10.
Let’s give a more concrete example. Lecanium scale is attracted to many species in our area, including oak trees and dogwoods. In general, we know that the insect larva settles on twigs in the fall through the winter. In the early spring, the female scales mature and lay eggs. In late May, crawlers emerge, move to leaves, and begin to feed. When we calculated the GDD for spring 2018, we expected to observe the crawlers beginning on May 23 (933 GDD, for what it’s worth).
Depending on the pest, we typically know when the females lay their eggs, when and where the crawlers hatch, and when the nymphs molt the first and second times (i.e., how many generations present themselves, the length of their lifecycle, if the generations overlap). And, with that, we know when and how often to treat.
Did you know? Phenology is the study of periodic plant and animal lifecycle events (including pests) and how these are influenced by seasonal and inter-annual variations in climate, as well as habitat factors, such as elevation.
The short answer: it depends.
Some treatments are monthly, others seasonal. Some require two treatments; others three. Some recommended protocols require annual treatments over a number of years. Others require treating the soil to prevent reemergence.
Sometimes pests are sprayed in the spring, summer, and fall. Other pests may only be sprayed when the adults appear or when the mites are active. Some spray treatments, like those for scale and mealy bugs, are typically effective only on crawlers.
The good news is that you don’t have to know what to do and when to do it — we do. We got you covered.
Did you know? With emerald ash borer, you want peak amounts of insecticide in the xylem of the tree when eggs hatch and the larvae start to feed. They won’t even know what hit them! (And, yes, we know those are a different type of eggs hatching but they’re picture perfect.)
As we see it, loosely defined, integrated pest management (IPM) is the process of solving a wide range of pest-related problems while ensuring the safety of people and the surrounding environment.
When it comes to trees and shrubs, Carolina Tree Care incorporates IPM practices to manage tree- and shrub-specific pests and prevent long-term damage; however, we view ourselves as plant health care experts first with the right level of knowledge in tree- and shrub-related pest management.
Well, if you’ve read this far and are still unsure, please give us a call. We’re happy to take a look at your property and let you know if there’s anything that may be of concern either near-term or in the future.
Whether you’re in Concord, Charlotte, or any town in between, our professional arborists are your neighbors. Most of us were born and raised here, and we are lovers of all things North Carolina — from the Panthers to the crepe myrtles. We’re tree huggers through and through.
We’ve studied the Carolina landscape all of our lives, know the products that work best in this region, and have created a tailored approach based on the regional vegetation. Importantly, we care about the health of your trees and will work with you on the best course of action.
And we firmly believe that the natural world is even more interesting than social media. It’s our passion. (Feel free to read more About Us!)
While North and South Carolina terrain stretches from the beaches of the Atlantic coast to the Blue Ridge Mountains, most of the state vegetation is primarily categorized in USDA Zones 6 and 7.
What You May See
|Cherry leaf spot|
|Cercospra/Passalora needle blight|
|Phytopthora root rot|
|Fire blight/bacterial blight|
Scale insects, or landscape arthropod pests, usually fall into two general categories: soft scales that usually generate once per year (Coccidae) and hard or armored scales that usually have several generations per year, depending on the species (Diaspididae).
Common Pests found in North Carolina
Related Trees (Hosts)
|Cottony camellia scale||Camellia, Holly|
|Crepe Myrtle bark scale||Crepe Myrtle|
|Gloomy scale||Red maple, Snowbell (Styrax)|
|Japanese maple scale||Japanese maple, Dogwood, Yellowwood|
|Lecanium scale||Oak (water and willow), Dogwood, Redbud|
|Obscure scale||Oak, Pin oak, Willow oak|
|Tea scale||Camellia, Holly|
|White peach/prunicola scale||Prunus, Mulberry, Ligustrum|
|Crepe Myrtle aphid||Crepe Myrtle|
|Wolly hackberry aphid||Hackberry|
|Azalea lace bug||Azalea, Rhododendron, Pieris|
|Cankerworm||Oak, Maple, Dogwood|
|Seiridium canker and box canker||Leyland Cypress|
|Orange striped oakworm||Oak|
|Bagworm||Leyland Cypress, Juniper|
|Cool season spider mites||Boxwood, Needled evergreens|
|Warm season spider mites (e.g., two-spotted spider mite, European red mite, oak spider mite, spruce spider mite)||Broad leaf trees and shrubs|
|Ambrosia beetle||Oak, Maple, Crepe Myrtle|
|Black turpentine beetle||Pine|
|Elm bark beetle||American elm (Dutch elm disease)|
|Pine engraver beetle and southern pine beetle||Pine|
|Redheaded pine sawfly||Pine|
|Emerald ash borer||Ash|
Did you know? Soft scale insects insert piercing mouthparts (called stylets) into a tree and suck out large quantities of liquids, which presents a waste disposal dilemma. The pest voids the waste in the form of sticky honeydew, which damages cells and leaf production — and can completely defoliate a tree.
While we have a lot of information on this page, we also keep our readers abreast of plant health care issues through our regularly updated blog. Feel free to search the blog at any time, but below is a quick reference of blog topics on tree diseases and pests for you.