Have you ever hesitated to use a pesticide because you were not sure how to mix it, where or when it should be applied, or what threat it posed to bees, wildlife, pets or people? All of this, along with other essential information, is listed on every pesticide label. Reading the label before you buy or use a pesticide will help you decide which product is right for your pest problem, how to correctly apply it, and what risks are involved.
First, know your pest
There are many different pesticides available for home gardeners. These include herbicides to kill weeds, insecticides to kill pest insects, and fungicides to control plant diseases. Some contain synthetic chemicals while others are made from natural materials such as minerals, bacteria, or plant derived chemicals.
Whether you are dealing with a weed, insect, or plant disease, the first step to using any of these products effectively is to make sure you have the problem correctly identified.
Pesticide labels list which pests they can be used to treat. Using a pesticide on a problem it will not control wastes your time, money, and can harm beneficial insects, water quality, and wildlife. If you are unsure which pest you are dealing with contact your local Cooperative Extension office for help.
The ingredient in a pesticide that harms a pest is known as the product’s active ingredient. Just as on medicine bottles, pesticides must list their active ingredients on the label. These can usually be found on the front of the packaging. Knowing what active ingredient is in a pesticide allows you to compare one product to another. It also allows you to look up active ingredients on websites such the Extension Toxicology Network, extoxnet.orst.edu, to find out more about their potential effects on people and the environment.
When and how to apply
Not sure what type of plants or under what conditions you can use a pesticide? Check the label. For example, some pesticides should not be applied to edible crops while others should not be used on plants in containers or those that are drought stressed. Most pesticides should not be applied during hot weather, when temperatures exceed 90 degrees, or when rain is expected in the next 24 hours. Some herbicides should not be spread on certain soil types or over the rooting area of trees and shrubs. No pesticide should be sprayed or spread near any body of water or stormwater drain unless it is specifically labeled for aquatic use.
When pesticides fail to work it is usually because they were not mixed or applied correctly or the wrong product was used because the pest was not accurately identified. Directions for mixing and applying pesticides are included on the label. These directions will tell you how much to mix, where and how to apply them to the plant, how many days must pass between applications and if there are limits on the number of time a product can be used in a year.
People, pets and wildlife
Other essential information contained on a pesticide’s label include first aid instructions, protective clothing and equipment you should wear when mixing and applying, and hazards to wildlife, including bees. Many insecticide labels include statements about their toxicity to bees, which is often high. To reduce the risk of harming bees and other beneficial insects, do not spray plants when bees are active and avoid spraying open flowers. Natural products are often less toxic to bees because they break down fast, reducing the amount of time bees are exposed.
For pesticides that can be sprayed on edible plants, make sure to check how long you have to wait after spraying before you can harvest. This time is known as the post harvest interval (PHI) and can range from a day to weeks or months. The label will also tell you how long you have to wait before people or pets can enter the treated area. This is usually after all sprays have dried completely but additional restrictions exist for some products.
Reading the label thoroughly before applying a pesticide is more than just being an informed consumer or considerate neighbor, it’s the law. For advice on pest identification and control, contact your local Extension office. If you live in PenderCounty, call 910-259-1235. In NewHanoverCounty, call 910-798-7660. In BrunswickCountycall 910-253-2610, or visit ces.ncsu.edu/where you can post your questions to be answered via the ‘Ask an Expert’ widget. Visit the Pender Gardener blogto stay up to date with all the latest gardening news, pendergardener.blogspot.com/.
Charlotte Glen is a Horticulture Agent with Pender County Cooperative Extension of NC State University, College of Agriculture & Life Sciences. She can be reached via e-mail at Charlotte_Glen@ncsu.edu.