Fall Tree and Pest Manual
Fall is one of the best times to nourish and care for your trees! Our Fall Tree and Pest Manual will show you how.
Updated September 26, 2022
Late summer and early fall are interesting seasons from a plant health care perspective. Some insects lay their eggs at this time of year, while others are just joining Tinder with big plans for the spring. We can handle both.
In our Fall Tree and Pest Manual, we’ll share what you may see on your trees in the fall and which treatments you should add to your fall tree care checklist. We’ll also give you a heads up on the tree care treatments you should schedule right now to prevent issues in the spring.
Our Fall Manual covers:
Pests to look out for in the fall:
Fall webworm and orange-striped oakworm
Worms (aka caterpillars) are the larval stage of moths and butterflies that eat foliage. Depending on when they first appear, we classify them as early- or late-season defoliators. Late-season defoliators, like fall webworm and orange-striped oakworm, are less harmful than early-season defoliators since their host (the tree) has already made most of its food for the season.
Late-season defoliators typically first show up in late July and may last until early October. Generally, late-season defoliators are not treated, but there are some exceptions, including:
- Repeated and/or large defoliation events, which can have a significant effect on the tree’s long-term health.
- Nuisance situations where waste (poop) is excreted over a sidewalk, deck, pool, parking area, etc.
Cool season spider mites
Another type of pest you may see in the fall is the cool season spider mite. Cool season mites are tiny arachnids that feed on the sap in foliage. They’re most active in the cooler weather of spring and fall when daytime highs remain below 85℉.
Cool season mites are hard to see with the naked eye; you’re more likely to notice the damage their many tiny feeding spots cause. Foliage that’s normally green will look bronzed, yellow, and/or white. This type of damage is called stippling.
Heavily infested foliage can also become covered with an almost invisible webbing.
Are cool season mites a threat to your trees and shrubs? It depends. The good news is that spider mites have a lot of natural enemies that can usually keep the population in check. But if you find your infestation particularly heavy, a treatment could help.
Treatment options for pests that attack trees and shrubs in the fall
Here’s what you need to know about your treatment options for worms in your trees:
- Foliar treatments take effect in 1-2 days, but typically only last 2-4 weeks. When applied early in the season, additional treatments may be needed for season-long control.
- Soil-injected treatments take effect after 2-4 weeks, but last longer – typically 8 weeks or so.
- Trunk-injected treatments take effect after 2-4 weeks and can provide control for evergreens into the following season when applied late enough in the season.
- Pruning can be a quick way to remove nests and webs if the affected branches are reachable and there aren’t too many of them.
Foliar and soil-injected treatments can also be used to control cool season mites.
Add these soil services to your fall yard care checklist
You know that the condition of a plant’s soil plays a big part in its growth, development, and overall health.
Trees don’t need as much water in the fall, and they aren’t spending as much energy fending off pest and disease infestations as they do in the spring and summer. And deciduous trees are headed into dormancy for the winter.
Because of all that, your trees are typically a lot less stressed in the fall, making this season one of the best times to do any soil work.
Boost the health of your trees by scheduling these services in the fall:
Pale, yellow, and/or off-color leaves.
Leaves that are smaller than usual or changing color and dropping early.
Fewer flowers or fruit.
Slow growth or reduced overall vitality.
If you’ve noticed any of these issues with your tree, it may be nutrient deficient.
Depending on the species, trees need 16-19 essential elements to grow and function. But since most urban landscapes are nutrient deficient because of their highly altered soils, many trees are left without the nutrients they need. The nutrients trees could get from fallen leaves is often raked away, plus many trees have to compete for nutrients with turf.
That’s why most urban trees could benefit from supplemental fertilization. Fertilization restores missing nutrients to your soil to improve the health of your tree.
Is the soil around your tree compacted? Soil compaction is pretty common in urban landscapes. In fact, it’s a top stressor for urban trees. Heavy machinery rolling through your yard, parking cars under your tree, or even years of walking through the same area can tamp down the soil around your trees.
Compacted soil makes life harder for your tree. Water and oxygen can’t penetrate overly compacted soil, and neither can any new roots your tree produces.
We offer different levels of root rehabilitation to restore pore space and add nutrients to the soil.
Root flare excavation
The root flare is the bottom part of your tree where the roots merge into the trunk. When it’s covered up by soil and/or mulch, moisture can get trapped against the bark and eventually waterlog it. Soil and/or mulch can also block the exchange of oxygen and carbon dioxide for the tree.
Root flares end up covered up for a variety of reasons. Sometimes trees are planted too deeply, and other times the tree just naturally settles deeper into its planting hole. Improper mulching or grade changes during construction projects can also leave your tree’s root flare covered up.
If you’ve noticed foliage yellowing, early leaf coloration and drop, or upper crown dieback, a buried root flare could be behind it all.
You can use a shovel to expose your tree’s root flare if it’s not buried too deeply, but be careful! Bark in the root flare area is delicate — you could inadvertently hurt your tree while trying to remove the soil or mulch around it.
It may be better to just leave it to our professionals. We have specialized equipment to safely expose root flares.
Ready to cross these services off your checklist?
Request a consultation now!
Spring fungal diseases you’ll want to protect against in the fall
Spring fungal diseases, like anthracnose and leaf spot, are spread and maintained via spores that over-winter on fallen foliage and other tree parts. As temps warm and moisture increases in spring, these spores serve to re-infect the new tree foliage as it begins to form.
When the infection is severe enough, the tree may lose its foliage prematurely, and when this happens repeatedly, the tree may not be able to make enough food for itself via photosynthesis.
Consequently, the tree’s long-term health may begin to suffer. In North Carolina, we often see this with cherry and dogwood trees.
When it comes to fungal infections, it’s all about prevention versus eradication. Treatment must begin and continue throughout the early spring vulnerability period when new foliage is being formed.
Unfortunately, we are often called later in the season, when it’s already too late to treat effectively. To be more confident in your treatment, schedule your spring fungicidal treatment(s) in the fall. We’ll get you on the calendar and be able to treat before it’s too late.
Treatment for spring fungal diseases
Here’s what you need to know about your treatment options for tree fungal diseases:
- Fungi reproduce and spread via spores, so reducing residual spores via sanitation is important. This means raking up infected foliage that has fallen around the base the tree. It also means pruning out dead branches and limbs.
- These actions will reduce the level of residual spores and lessen the opportunity for spores to re-infect your tree in the spring. Note: If your trees are disease-free, leave as many leaves on the ground as you’re comfortable with. They’re good for fertilization!
- Come spring, we can apply foliar fungicides just prior to and while the new growth is forming to significantly reduce reinfection rates.
- Both organic and traditional synthetic fungicidal treatments are available.
Fall is a great time to prepare your trees and shrubs before the dormant season arrives, but DIY projects can be time-consuming.
Let us handle it instead.
Request a consultation to get in touch with your area’s arborist representative today!
But wait, there’s more on tree bugs and pests!
While we have a lot of information on this page and even more on our I Have Tree Bugs! 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 you may find interesting.
Seasonal advice for healthy trees
- Free Your Tree’s Root Flare
- Early Season Defoliators vs. Late Season Defoliators
- Should You be Fertilizing Your Trees?
- It’s Time to Schedule Your Root Rehabilitation Service
- Strengthen Your Trees Against Late Summer Storms With These 7 Tips
- Don’t Let Fallen Tree Leaves Go to Waste
- Why Fall is a Great Time to Plant a Tree
- How to Install Mulch Like a Professional
- Got Fall Webworms? Worry No More.
Carolina Tree Care would love to work with you.
We understand the importance of caring for your trees in a safe, responsible way.
Contact us today to work with a team you can trust.