A few Guidelines for safely using pesticides for gardeners - U of I Extension

News Release

A few Guidelines for safely using pesticides for gardeners

This article was originally published on July 17, 2018 and expired on October 17, 2018. It is provided here for archival purposes and may contain dated information.


BLOOMINGTON, Ill. – “As a greenhouse grower, her primary duty was not growing plants, as her title would imply but to scout for pests and spray pesticides,” mentions University of Illinois Horticulture Educator, Kelly Allsup.


For 7 years, Kelly watched the population numbers of greenhouse pests like spider mites, thrips and aphids rise and fall through various spray events. Her number one goal was to understand and use these pesticides to the get the greatest results so that she could limit wearing the marshmallow man suit. In this job, she made many mistakes in applying pesticides with a potential compromise to her own health. That is why today….she gives you gardening guidelines for using pesticides correctly to improve their efficiency and your own safety.


Do not spray pesticides on windy days. Glyphosate and other weed killers will kill your prized trees and plants even if just a small amount of pesticide hits the leaves. Once absorbed glyphosate travels to the roots preventing the plants from making building blocks to grow. This is why you absolutely do not spray this herbicide on the suckers of your crabapple. 


Wear long pants, shoes, socks, eyewear, and rubber gloves when spraying pesticides. The active ingredient in pesticides and other ingredients that make up the product may irritate your skin and eyes. These clothes should also not be laundered with other clothes but should get their own hot water wash.


If you are spraying an insect pest population, make sure you get full coverage of the plant covering the tops and undersides of the leaves. The smaller the particle size the better the coverage, however, it may be more likely to go off target.


Do not spray on hot days as volatilization will occur contaminating other plants.


Only spray plants with pests do not spray everything in the yard. There are beneficial insects in your yard that are usually doing a better job at eradicating pests than pesticides and you would hate to lose their services. If the pest and plant you are spraying are not on the label, do not spray. Read the label and if it says to follow up in 7-10 days then do it. You may be getting the next generation of pests that you could not kill while in the egg stage.


Use biological based chemicals like Azadirachtin, Neem oil, Spinosad, Beauvaria bassiana and limit spraying when bees are out. They are less likely to kill beneficial insects and bees than the pesticide you have in your garage right now.


Most diseases are prevented and not cured. Those who are spraying for diseases knew about the problem last year and are taking steps this year to prevent.


Always identify the pest, weed, disease before you spray. Look for the good guys!


Source: Kelly Allsup, Extension Educator, Horticulture, kallsup@illinois.edu

Pull date: October 17, 2018