Pesticide safety is always an important consideration when caring for your landscape plants. If used correctly, pesticides can help improve the health and longevity of our plants. However, if used incorrectly, they can harm and even kill our plants or our neighbor’s plants.
Pesticide is the general term for any type of chemical we apply to our plants. This can include insecticides for controlling insects, herbicides to help us control weeds, and fungicides to help with fungal diseases in our plants.
Always read and follow the pesticide label instructions. Remember, the label is the law. Pesticides can only be used in the location and on the plants that are listed on the label. For instance, Tordon is a common pesticide used along roadsides and in fencerows as a stump treatment for weedy tree species growing where they are not desired. Tordon and many of the other products used on parking lots have varying degrees of solubility and will move with water to non-target areas and can cause damage. These products can move off of the parking lot to nearby greenspace and through the rootzones of trees to nearby plants causing damage and possibly death to your desired plant species. That is why these products are only to be used in the locations listed on the label, and not in your home landscape. Instead of using Tordon, a good alternative would be one of the brush killers that are found in many different formulations that are labeled for use in our landscapes and won’t harm our non-target plants.
Along with following the label instructions, make sure you are applying the pesticide at the correct rate for best control. The company that developed the product went through a great deal of research to ensure that they gave you the correct amount to apply to your weeds or insects. Do not apply more than what is recommended, and remember to be patient, the death of a weed takes around a week for many general use herbicides.
We have been seeing a great deal of weeds in our lawns this year, and with all of the rains, it has been hard to spray chemicals or have effective treatments for those weeds. However, we should now begin putting our 2,4-D products away for the summer months. 2,4-D can volatilize, or turn into a gas, and move to non-target plants in temperatures of 80 degrees or higher for up to 72 hours following application. 2,4-D should not be used in the summer months due to this issue. Also, most of the broadleaf plants we typically use 2,4-D on will be controlled better in the fall. So enjoy the flowers in the lawn until fall comes and mark your calendar for 2-3 applications of a 2,4-D product in September and October when the temperatures are cooler and the plants will take the chemical back into the roots with their winter storage nutrients.
Another issue with using pesticides, insecticides in particular is the harm to pollinating insects. June 15-21, 2015 was National Pollinator Week. We need to make sure that we are applying chemicals at the right rate, right time, and right location to not harm beneficial insects. If it is a plant that bees or butterflies are common on, use insecticides only as necessary and at dusk when the pollinator insects are not around and avoid spraying the chemical on the flowers. If the pest is a caterpillar, like bagworms, choose Bt instead of general insecticides. Bt is only harmful to caterpillars and won’t harm bees or beetles, but it will harm monarchs so be careful around milkweed plants with Bt. If you are spraying any kind of chemical on your lawn, it is beneficial to bees if you mow the lawn first to cut off any blooms that bees may forage on, reducing the risk of the chemical getting on the bees.