In gardening terms, pesticides would most commonly be considered those chemicals or materials used to control insect pests on plants. In a broader sense, one would also add fungicides and herbicides to the list.

During the second half of the 20th Century, society became much more conscious of the impact pesticides can have on individuals and the environment. In 1962, Pennsylvania naturalist Rachel Carson authored the famous book "Silent Spring" which succeeded in opening eyes to the risks posed by insecticides, primarily the use of DDT.

The title referred to a silent spring without the sound of birds singing. On the other side of the aisle, pesticide use advocates would quickly remind you that without pesticides, food production yields could drop 40% while food and plant quality would suffer. Also, that insect-borne diseases like malaria would be more severe without the use of pesticides. 


Therefore, today's talk has evolved to 'thresholds' -- meaning what sort of economic or aesthetic threshold is acceptable without applying pesticides. In layman's terms, that means how many brown spots on your front lawn are 'aesthetically acceptable' or how much crop damage can a farmer sustain before it crosses an 'economic threshold.' 
The Middle Road  
Public debate, university research and practical application have landed us somewhere on the middle road, focusing on responsible pesticide usage. Instead of spray first and ask questions later, it's become the norm to practice Integrated Pest Management (IPM). 
IPM has several basic tenets: 

  • Is pesticide usage really necessary, or is the level of damage acceptable? 

  • Can satisfactory control be achieved with products such as dormant oils or insecticidal soaps? 

If using a pesticide is deemed necessary: 

  • Identify the affected plant

  • Identify the pest

  • Use the least toxic pesticide available that is labeled for control

  • Time the application to when the insect is most vulnerable

  • Read and follow label directions

The most important thing an individual can do before working with a pesticide is READ THE LABEL. Be sure to read the ENTIRE label since it contains critical information concerning the proper handling and use of the product. 

  • Keep pesticides out of the reach of children. Never transfer pesticides from their original, labeled container into an empty drink container which might allow it to be mistaken for a beverage. Oral pesticide poisoning ranks #1 in children!

  • Don't use the same sprayer for weed control and insect control. Mark one sprayer "WEEDS." Metal sprayers cannot be used with some pesticides, so read the label.

  • Use a low pressure regulator to help prevent spray "drift" onto non-target areas. High pressure spray mists can easily drift onto non-target areas.

  • Make applications in the cool of the day (early morning or evening) when there is little to no wind. Spraying in hot, humid weather will cause phytotoxicity from some pesticides.

  • When spraying plants visited by bees and other pollinators, do so when these insects are not active. Late evening is usually considered the best time.

  • Spray when no rain is forecast for 24 hours unless the product specifically calls for watering it in.

  • Dress properly: Protect eyes and skin, wear approved chemical resistant gloves and boots, and wear an approved respirator if possible.

  • The greatest risk comes from handling the concentrate, so wear approved gloves and be sure to protect your eyes from the splashing that can occur when adding pesticides to the spray tank.

  • Triple-rinse pesticide containers before disposal, using those rinses in your final spray application.

  • Follow recommended re-entry times to protect pets and people after an area has been sprayed.



US National toll-free number


A professional plumber is usually the best choice for plumbing problems, just as a professional applicator is usually the best choice for controlling pest problems. They have the experience, training, and correct product to address your pest problems. Homeowners often expose themselves and others to pesticide poisoning by improper handling and use of pesticide products. 
It seems commonplace to see a well-intentioned homeowner outside on a Saturday morning in a t-shirt, shorts and flip-flops spraying a tree (and himself) with insecticide. One of the primary avenues of pesticide poisoning is dermal exposure, not to mention how much he might be inhaling and absorbing through his eyes...  
More questions arise: Is he using the right product, on the right plant, at the right time? Did he double the recommended rate wrongly thinking that twice as much is better? Did he read the label? Is his child in the garage handling, or worse yet, drinking the product while he's in the front yard spraying?

The #1 cause of pesticide poisoning in children is oral exposure. Never transfer a pesticide from its original packaging and never put a pesticide in an old beverage container!

Keep pesticides out of the reach of children!

Commercial pesticide applicators in Pennsylvania are required to hold a pesticide license issued by the Pennsylvania Department of Agriculture. Under that license, the applicator must carry certification in the proper category. For example, a lawn care applicator must have Category 07 [Lawn & Turf] on his or her license, while a technician spraying trees and shrubs must have Category 06 [Ornamental & Shade Tree]. In addition to paying an annual license fee, these individuals must complete pesticide update training every 3 years. 
Who do you think is safer handling pesticides?



Four routes of pesticide poisoning: 


  • Oral - mouth

  • Dermal - skin

  • Inhalation - lungs

  • Eyes

One sign of pesticide exposure is having pinpoint pupils.


Pesticide labels contain 'signal words' that indicate one of three levels of toxicity. These levels are based on the LD50 of a pesticide (the amount required to kill 50% of the animals in a test population). 
Simply put, the three levels of toxicity are: 

  • CAUTION - the least toxic chemical pesticides.

  • WARNING - mid-level toxicity pesticides.

  • DANGER-POISON - the most toxic category of pesticides. Only available for purchase and application by a licensed applicator.

It's always recommended to use the LEAST TOXIC pesticide available to treat your particular need.


Some individuals are "hypersensitive" to pesticides that cause little to no reaction in other people.  The State of Pennsylvania sends a quarterly "Pesticide Hypersensitivity Registry" of hypersensitive individuals to all commercial pesticide applicators in the state.  There is a mandatory process for commercial applicators to provide advance notice to these individuals when an application is to be made within 500 feet of their work, school or residence.
If your doctor can medically certify that your name should appear on this hypersensitivity registry list, contact:
Pennsylvania Department of Agriculture (PDA)
Bureau of Plant Industry
2301 N. Cameron St.
Harrisburg, PA  17110-9408
Main Phone: (717) 772-5231

If someone in your family is hypersensitive to pesticides, it would also be a good idea to personally notify your neighbors. While commercial applicators are mailed a booklet several times a year listing registered individuals, neighbors presently have no way of knowing unless someone tells them.

CHEMSWEEP - Safe disposal of pesticides

Pennsylvania has a program to help homeowners and businesses dispose of old or unwanted pesticides. Various counties participate in the CHEMSWEEP program each year, and it provides an excellent way to protect our environment from hazardous or illegal dumping. Call (717) 772-5210 for more information.


Mr. Yuk 


Disclaimer: This page attempts to cover the basics of a very complex subject and the information may be dated or incomplete. is not responsible for any errors or omissions.



Pesticides storage

Controlling weeds

Common garden insects


home | terms of use | contact | search | site map
Copyright 2017  DONNAN.COM  All rights reserved.