"Damage to tree leaves and stems is often the first sign of a bigger tree problem, possibly an insect infestation," Newborn says. "Look for other symptoms to pinpoint the issue."
Use Davey's checklist below to pinpoint what insect could be damaging your trees and how to stop it.
Symptoms: Leaf curling, twig dieback, a sugary substance called "honeydew," black, sooty mold and stunted growth
What insect is damaging my tree: Aphids, the resident "plant lice."
What do aphids do: They feed on tree leaves and stems, prevent proper nutrient and sunlight intake and cause premature leaf drop.
How to control aphids on trees: Stop aphids using horticultural soap treatments or insecticides.
Symptoms: Chunks of leaves chewed down to the veins, browning leaves around the top of the tree canopy and leaves falling in summer
What insect is damaging my tree: The flying, feeding Japanese beetle.
What do Japanese beetles do: They eat entire tree leaves in warm, sunny weather, often leaving behind only the skeleton.
Most common tree victims of Japanese beetles: Crape myrtle, birch, littleleaf linden, crabapple, purple leaf plum, Japanese maple and Norway maple.
How to control Japanese beetles: Apply one or two pesticide treatments a few weeks apart, from mid-June through August.
Symptoms: Silky "webs" in trees, chewed leaves, mild to severe leaf loss and branch death with no regrowth on evergreens
What insect is damaging my tree: Bagworms, the camouflaged critters.
What do bagworms do: Bagworms consume tree leaves, often on the sly, until severe damage occurs.
Most common tree victims of bagworms: Juniper, arborvitae, cedar, spruce, honey locust, linden, willow, maple, oak, birch, elm and poplar.
How to treat bagworms in trees: As soon as you spot an infestation, handpick and destroy all bags. If that's not practical, your local arborist can apply an insecticide treatment.
Why are your tree leaves turning yellow in summer?
Test for dry soil. "If trees aren't hydrated, the leaves can turn yellow as they try to conserve water," Newborn says. Test your tree's moisture by sticking a screwdriver into the soil. If it's hard to push in, chances are the tree is thirsty and could use a deep watering.
Check soil moisture. "Most people want to water their tree more if it's yellow or losing leaves. But overwatering could actually be the problem," Newborn notes. If the screwdriver test proves there's moisture deep into the roots, Newborn recommends watering less.
Inspect and treat. "If you used the checklist above and ruled out an infestation, see if your tree has a deficiency called chlorosis, which strips leaves of the chlorophyll needed to keep them green," Newborn explains. Begin by performing a soil test and adding any necessary soil amendments. Fertilizer also replenishes lacking nutrients, which in turn helps your tree.
Will my tree rebound on its own after a storm?
First and foremost, your safety is the top priority. If storm damage left large hanging branches or broken power lines, call your arborist to assess the situation immediately.
Once you deem it safe to be outside, walk around your tree and look for these danger signs:
Hanging or broken branches
Splits in tree branches
Broken or uneven treetop
Decay, holes, cracks or cavities in the tree trunk
With more than 9,000 employees throughout North America, The Davey Tree Expert Company provides solutions for residential, utility, commercial and government clients. Rooted in research, the company's vision is to achieve balance among people, progress and the environment. Tree experts since 1880, Davey provides diversified tree services, grounds maintenance and environmental services. Davey is one of the largest employee-owned companies in the U.S. and is headquartered in Kent, Ohio.
All articles are copyrighted and remain the property of the author.
By Justin Hancock, Monrovia Horticultural Craftsman
Photographs courtesy of Monrovia
Labor Day may represent summer’s unofficial close but now is a perfect opportunity to add late-summer perennials that will continue to beautify your landcare until fall arrives. click here for an article that identifies 9 perennials for late summer.
Click here to sign up for our monthly NEWSLETTER packed with great articles and helpful tips for your home, garden and pets!