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Collection: The Harmful Effects from Yard Chemicals to the Earth, Lakes, and Trees

Our planet needs help, Deblen is helping one yard at a time. The articles in this section highlight the harm conventional yard chemicals are inflicting on our trees, lakes, wildlife, and soil.

Nebraska Forest Service:

Herbicide Damage to Trees


Author(s): Laurie StepanekJustin EvertsonKyle Martens
Leaf cupping of an oak tree. This is typical of dicamba or 2,4-D exposure.

Herbicides can be effective tools for controlling unwanted weeds in the landscape. However, in recent years the Nebraska Forest Service has seen a significant increase in unintended herbicide damage to trees and other landscape plants. You can assist us in documenting damage across Nebraska. Please note the NFS is not a regulatory agency. 


Damage symptoms

Damage symptoms vary with the type and concentration of herbicide, the plant exposed and its stage of growth, and environmental factors. Common symptoms may include:

  • Deformed foliage: leaf cupping, curling, twisting, puckering, strapping (narrow, elongated growth)
  • Twisted, curled or stunted stem and branch growth
  • Clusters of stunted shoots or leaves
  • Discolored foliage: yellow, white, reddish, purplish, or abnormally light or dark green
  • Leaf scorch (leaf edges turn tan to brown), flecking, or complete browning and death of leaves
  • Defoliation (leaves or needles drop from the tree)
  • Branch dieback or death of entire tree

Damage from weather, insects, and diseases can be confused with herbicide damage. Your local extension office, the Nebraska Forest Service, or the Nebraska Department of Agriculture may be able to assist with identifying herbicide injury.

Ag machine sprays in field
Trees leafing out with new spring growth are particularly sensitive to herbicide drift. Visit for locations of growing operations near you.


Sources of herbicide exposure

Dandelions in a violet flowerbed
Root uptake by trees can also occur with many lawn herbicides, particularly those for control of clover, violets and other tough broadleaf weeds.

Drift: Herbicides can move through the air from the site of application to nearby areas, causing damage to trees and other plants.

Possible sources of drift include the use of 2,4-D and dicamba in spring in an effort to control dandelions and other weeds in home lawns and for control of winter annual weeds in crop fields. These herbicides can be particularly damaging to tender foliage emerging in spring, especially on sensitive trees such as oaks, redbud, honeylocust, Kentucky coffeetree, elms, and maples.

Many formulations of dicamba and 2,4-D are quite volatile. This means the herbicides can form a gaseous vapor during or following application— sometimes even days later. Warmer temperatures (typically above 85 degrees) increase volatility, and may result in the vapor moving long distances from the application site on warm spring and summer days.

Root uptake: Tree damage can also occur through root uptake from herbicides that move through the soil. These include herbicides used to control roadside vegetation or to keep the ground “clean” around buildings, along fence lines, and on sidewalks, driveways and gravel strips. Many are labeled for control of “brush and woody weeds” and can cause significant damage to trees. Even trees located some distance from the application site may be affected since tree roots can extend well beyond the canopy of the tree. Dicamba, picloram (Tordon), bromacil (Hyvar), and prometon (Pramitol) are just a few common examples.

Another “bare-ground” herbicide, glyphosate (Roundup), controls most weeds when applied to the foliage. Glyphosate is generally inactive in soils; however, some Roundup products contain different or additional active ingredients, which may be picked up by roots. Check the label!

Root uptake by trees can also occur with many lawn herbicides, particularly those for control of clover, violets and other tough broadleaf weeds. Care must be taken to apply the appropriate rate when used in landscapes with trees.

Steps you can take

Dandelions in a violet flowerbed
Herbicide uptake by this tree's root system is the likely cause of its decline. 

To lessen the likelihood of herbicide damage to your trees and those of your neighbors, follow these guidelines:

  • Read and follow ALL herbicide label directions, particularly restrictions that help limit drift, vaporization, and runoff. Look for precautionary statements regarding trees.
  • Be aware of surrounding properties with sensitive vegetation including parks, gardens, windbreaks, landscape nurseries, orchards, vineyards, organic farms, and native woodlands and other natural areas. Visit for locations of growing operations near you.
  • Most damage occurs in spring when trees and other plants are leafing out with susceptible new growth. Try to shift weed control to fall when many weeds are more easily controlled and damage to trees is reduced.
  • Monitor temperature, wind speed, and wind direction. Avoid spraying on warm, windy days.
  • Adjust sprayer nozzles to a coarser spray to reduce drift.
  • Be especially careful using herbicides that control “woody brush” or include trees or shrubs on the list of weeds controlled.
  • Keep in mind the extensive reach of tree root systems—often well beyond the canopy edge.
  • Use extreme caution when treating stumps located near desirable trees. Over-application may contaminate the soil around the stump. Alternatively, the chemical may move into the soil from the stump roots.
  • When possible use alternate methods of weed control such as cultivation, mulching, use of cover crops, and mowing weedy tree sprouts.
  • Though trees can sometimes be killed relatively quickly by unintended herbicide damage, some of the worst damage builds slowly over several growing seasons. Trees often can recover from light and occasional damage, but repeated damage year after year will almost certainly shorten the lifespan of our most important trees.
  • Become familiar with the more common herbicides and how they may be safely used. Homeowner herbicides include 2,4-D, dicamba, triclopyr, MCPP, and glyphosate. Professional herbicides include these plus imazapyr, picloram, bromacil, prometon, tebuthiuron and many others.

Learn more

To learn more about potential herbicide damage to trees and other non-target plants contact your local UNL Extension Office or visit this website.

Growers of specialty crops can register at to raise awareness of their operation to surrounding applicators.

Photo courtesy: University of Nebraska-Lincoln, Pesticide Safety Education Program.


How Fertilizers Harm Earth More Than Help Your Lawn

Chemical runoff from residential and farm products affects rivers, streams and even the ocean

Dear EarthTalk: What effects do fertilizers, pesticides and herbicides used on residential lawns or on farms have on nearby water bodies like rivers, streams—or even the ocean for those of us who live near the shore?
-- Linda Reddington, Manahawkin, NJ

With the advent of the so-called Green Revolution in the second half of the 20th century—when farmers began to use technological advances to boost yields—synthetic fertilizers, pesticides and herbicides became commonplace around the world not only on farms, but in backyard gardens and on front lawns as well.

These chemicals, many of which were developed in the lab and are petroleum-based, have allowed farmers and gardeners of every stripe to exercise greater control over the plants they want to grow by enriching the immediate environment and warding off pests. But such benefits haven’t come without environmental costs—namely the wholesale pollution of most of our streams, rivers, ponds, lakes and even coastal areas, as these synthetic chemicals run-off into the nearby waterways.

When the excess nutrients from all the fertilizer we use runs off into our waterways, they cause algae blooms sometimes big enough to make waterways impassable. When the algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic species can’t survive in these so-called “dead zones” and so they die or move on to greener underwater pastures.

A related issue is the poisoning of aquatic life. According to the U.S. Centers for Disease Control (CDC), Americans alone churn through 75 million pounds of pesticides each year to keep the bugs off their peapods and petunias. When those chemicals get into waterways, fish ingest them and become diseased. Humans who eat diseased fish can themselves become ill, completing the circle wrought by pollution.

A 2007 study of pollution in rivers around Portland, Oregon found that wild salmon there are swimming around with dozens of synthetic chemicals in their systems. Another recent study from Indiana found that a variety of corn genetically engineered to produce the insecticide Bt is having toxic effects on non-target aquatic insects, including caddis flies, a major food source for fish and frogs.

The solution, of course, is to go organic, both at home and on the farm. According to the Organic Trade Association, organic farmers and gardeners use composted manure and other natural materials, as well as crop rotation, to help improve soil fertility, rather than synthetic fertilizers that can result in an overabundance of nutrients. As a result, these practices protect ground water supplies and avoid runoff of chemicals that can cause dead zones and poisoned aquatic life.

There is now a large variety of organic fertilizer available commercially, as well as many ways to keep pests at bay without resorting to harsh synthetic chemicals. A wealth of information on growing greener can be found online: Check out and the U.S. Department of Agriculture’s Alternative Farming System Information Center, for starters. Those interested in face-to-face advice should consult with a master gardener at a local nursery that specializes in organic gardening.

CONTACTS: CDC,; Organic Gardening Guru,; USDA’s Alternative Farming System Information Center,

EarthTalk is produced by E/The Environmental Magazine. 

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