'Tis the season... to use pesticides. Whether in need of weed control, fungicide control or pest control, gardeners often reach for products on hand or head down to a garden center to arm themselves with chemicals.
Likely as not, home gardeners will pick a product at random without knowing what it is intended for and how to use it. Before purchasing, always read the label and be aware of the product's purpose. Be prepared to invest in any protective gear specified on the label.
By their very nature, pesticides are poisonous. Designed to interrupt some part of a pest's biological process, a pesticide's effect on people or pets can vary from mild to deadly. The greater the degree of toxicity and the longer the exposure, the greater the risk. We can reduce risk either by decreasing the pesticide's toxicity or our exposure to it -- or both. Understanding the pest and following the instructions on the product label also will help decrease risk.
Know your pest -- identification is essential to responsible control. Use of a pesticide should be your last defense. Arm yourself first with information about the pest and alternative methods of control. For example, some pests, such as aphids, can be sufficiently controlled by a strong spray of water. Colorado State University Cooperative Extension agents and Master Gardeners can provide more information such as this.
If the use of a pesticide is necessary, know the pest's lifecycle. Some pests are vulnerable to control at certain stages in their lifecycle; in other stages, they cannot be controlled.
Select a pesticide that is appropriate for the pest and buy it in a quantity that is reasonable for your needs. Reduce the risk to yourself, family and pets, by purchasing the least toxic pesticide possible and by applying it only as directed. By law every pesticide label carries one of three signal words related to its toxicity -- in order of increasing toxicity. These words are caution, warning and danger. If possible, choose a product carrying the word caution over one carrying warning, and one carrying warning over one that says danger. Unless you have been battling the pest for more that two growing seasons and are reasonably sure the challenge is ongoing, buy only enough to see you through one or two applications. The typical pesticide has a shelf life of about two years. If you buy more of a pesticide than you need, you are left to deal with the effort and cost of disposal.
Should you choose a concentrate or a ready-to-use pesticide? Concentrates are more toxic than their diluted ready-to-apply companion products. Making at-home dilutions increases the potential for exposure and usually requires a greater level of protective gear.
Choose concentrates only if you know that you will use the product in two years or less. Using a permanent marker, it's a good idea to label the container with the date of purchase. And, before buying a concentrate, consider whether you are willing to invest in the appropriate safety gear.
After purchasing a pesticide or before using one previously purchased, read the label again. Following the signal word, (caution, warning or danger) the label will list the hazardous effects of the pesticide and will give directions for safe mixing and application. The more toxic the product, the more safety gear you'll require. Some ready-to-use products require that you avoid skin and eye contact and, that after application, you wash-up thoroughly with soap and water. More toxic or concentrated products can require a faceshield, goggles, chemical resistant gloves and footwear, long sleeves, and long pants.
Clothing worn during mixing and application must be washed separately from other household laundry before wearing it again. Be sure the gloves you use are matched to the label requirements - never use cloth, leather or household gloves. Clean all reusable protective gear after use and inspect it to make sure it is in good condition prior to using it again. If you are uncertain about anything related to the pesticide, call the National Pesticide Telecommunications Network at 1-800-858-7378. A highly qualified pesticide safety specialist can provide information about protective gear, its use and care, as well as answer any other questions you may have.
When applying a pesticide consider family members, neighbors and pets. Let neighbors with children and pets know when you use a pesticide near your property perimeter or on your lawn, especially if your yard is not fenced. Always abide by the product instructions for re-entering the treated area. Be especially vigilant when using products such as slug bait, which can persist in the garden for days, providing an attraction for young children and pets.
Finally, as with all medicines and household poisons, store unused pesticides in a secure location in accordance with the label instructions and out of the reach of children. Never transfer a pesticide product to a soft drink bottle, milk carton, or other pesticide container. The product's label is its source of identity and carries critical information. If a pesticide container leaks or if a spill occurs, the label also carries specific instructions on handling these situations. Check with your local health department prior to disposing of any pesticide. State and local regulations can be more stringent than the federal requirements that are listed on the product label.
Two telephone numbers to keep handy are:
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010