Do Lawn Chemicals Harm My Tree?

The impact of lawn chemicals on trees can vary depending on the specific chemicals used, their concentration, application rate, and the tree species in question. In general, some lawn chemicals can potentially harm trees if they are misapplied or used improperly. The best way to avoid harming your tree is to use a professional familiar with tree health care. 

Here are a few examples:

1. Herbicides: Herbicides are chemicals used to control weeds. If herbicides are applied too close to the base of a tree broadcast or sprayed directly on the tree’s foliage, they can potentially harm the tree by causing leaf burn, twig dieback, or even root damage. Some herbicides can also persist in the soil and affect the tree’s root system, potentially leading to long-term damage. Treatment to eliminate a weed without considering all the side effects can damage other plants. Therefore the pros and cons must be weighed.
2. Insecticides: Insecticides are used to control insects that may infest lawns, but they can also affect trees and plants. If insecticides are applied without consideration for all living things, the insecticide can potentially harm beneficial insects that help control pests. The insecticide can harm or kill pollinators, as well as other non-target organisms. This disruption in the ecosystem can indirectly impact trees by affecting their natural pollination or pest control processes.
3. Fertilizers: Fertilizers are used to provide nutrients to lawns and promote growth, but excessive or improper use of fertilizers can potentially harm or even kill trees. Over-fertilization can cause nutrient imbalances, which may negatively impact tree health. For example, excessive nitrogen can cause rapid growth, weak wood, and increased susceptibility to pests and diseases.

Not all treatments are a risk to your trees, the same goes for insects and fungus. With the correct knowledge, you can mitigate harming your trees if the right circumstances exist. Think about when you get sick with a scratchy throat, you can either let your immune system work through it and heal itself, or you can take antibiotics. If you take antibiotics, it will not only kill the infection/bad bacteria but it will also kill the good bacteria, causing your immune system to be more vulnerable to new infections. Overall having a lawn treatment does not necessarily mean it will harm your tree as long as the applicator considers the clients needs, the potential harm, and the benefits of treatments.

When an applicator considers the environment, pathogens/pest abundance, and the harm they can do to the potential host before treatment, the result of having a nice yard and healthy trees and plants will increase.