Could your trees be the victim of herbicide damage?
December 1, 2014
Have you noticed your tree, or trees, going into an unreasonable state of decline or seem to be stunted? Do you notice leaf curling or leaves that look cupped? Perhaps leaves are discolored or have brown dead spots? Your trees could be victims of herbicide damage. Even if you keep an organic landscape, your neighbors may not. If your neighbors have used an herbicide or weed & feed on their property, your trees could be collateral damage. It’s always good to talk with neighbors about what treatments they apply to their property that can affect yours.
How does this happen?
Some herbicides are selective; some aren’t. Selective herbicides are formulated to kill specific plants. Non-selective herbicides will damage or kill any vegetation they come in contact with. If herbicides are not applied properly and under the right conditions, your trees or landscape can fall victim to a neighbor’s herbicide treatment. Applying herbicides on a windy day can result in the chemicals drifting onto your property. Or, if they are applied on an exceedingly warm dry day, the chemicals can become volatile (vaporize into the air through evaporation). For example, if your neighbor has been using Roundup regularly to kill weeds near your trees, it could drift or become volatile, causing damage to your plants when it comes in contact with their leaves.
Weed & Feed products are a common silent killer of trees. Many contain the chemical atrazine, which shuts down the sugar making process of susceptible plants. One absorbed, the plant can no longer feed itself. For small weeds, the kill happens quickly. Large trees can often tolerate one application of such a project and have time to flush it from their systems before permanent damage is done. However, that depends on the time the product is applied and how often. They’re often applied in spring, which is the worst time for your trees. Atrazine will most hurt your trees as they are pushing out their new spring growth. While a large mature tree can tolerate one application of such a product annually, more applications can lead to the tree’s death. So, if your neighbor is putting down weed & feed and it comes in contact with your tree’s roots, you could have a serious problem.
Diagnosing herbicide damage on trees can be very tricky. Often, symptoms may appear similar to other pest or disease issues. An experienced arborist will look for many different factors to determine if your tree was damaged by herbicides.
Which kinds of herbicides are most dangerous?
There are a variety of herbicides that could negatively affect your trees. Here are a few of the most common ones.
Phenoxy herbicides: This includes products that contain 2,4-D. They cause curling of stems and leaves. After abnormal growth, leaves will appear chlorotic (yellowing) and necrotic (browning). Affects broadleaf plants.
Paraquat: Causes burning and necrosis on plants that they come in contact with. If spray drift is minor, affected plants may only be spotted with necrotic tissue on their leaves. Affects many types of vegetation.
Glyphosate is the main ingredient in Round-up and Kleen-up. When applied it causes yellowing, wilting, and browning of the leaves with death being the eventual outcome. Some trees or large shrubs, when sprayed, may not show injury until the following season, but will then appear stunted and chlorotic. Glyphosate is a non-selective herbicide that can damage your trees when it comes in contact with foliage through drift or evaporation.
Atrazine, Simazine and others are applied as weed & feed products or directly to the soil around driveways, fences and sidewalks to stop weeds. They move very slowly through the soil and can be absorbed by your tree’s roots. Symptoms of damage sometimes may not show up for a year. You’ll notice a slight yellowing and chlorosis around the margins and veins of the leaves. Healing from this type of herbicide damage can take years.
If you are trying to reduce the use of chemicals in your life, the landscape is a great place to start. Ready to be more eco-friendly for your family, pets and the environment? Give us a call to learn about our year-round fertilization SEASONS Program. We can also have the soil tested in your landscape so we’ll know exactly what your trees and plants need to thrive.