Chemicals for Lawn Care

Lawn care requires proper cultivation techniques, including pest and weed control, as well as proper feeding. Although there are organic methods of providing food to the lawn, and preventing damage by pests, chemicals are often used to handle the job. Knowing the chemicals and their purpose in the lawn will improve your lawn care technique.


Fertilizer provides the most important element for grass growth, nitrogen (N). Nitrogen is applied to the lawn at a rate specified by the grass variety, per 1,000 square feet. Nitrogen quickly increases grass growth and improves the green color. Too much nitrogen in the lawn causes “leggy” growth, making the grass top-heavy and susceptible to disease. It is important to check with your local cooperative extension for nitrogen application rates for your grass variety. Fertilizer is applied in a granular form or as a liquid spray.

Pre-Emergent Herbicides

Pre-emergent herbicides are used for the control of annual weeds in the lawn. Pre-emergent herbicides are chemicals sprayed into the soil to prevent weed seeds from germinating. To be effective pre-emergent herbicides are applied two to three weeks before the seeds are expected to germinate.

Post-Emergent Herbicides

Post-emergent herbicides kill weeds once they are established in the lawn. Post-emergent herbicides come in a spray form that is either sprayed onto the plant or into the dirt. Post-emergent herbicides work in a variety of ways, destroying the plant’s metabolism or preventing photosynthesis. According to the University of Minnesota post-emergent herbicides are best applied when the temperature is between 60 and 80 degrees F and there is no wind that might cause drifting.


Pesticides are used to control insects in the lawn. Proper identification of the bug before the purchase of pesticide is required to determine the best chemical control. Pesticides must be applied according to the label instructions wearing the required safety equipment to prevent injury.

Keywords: lawn chemicals, lawn herbicides, lawn fertilizer

About this Author

Cleveland Van Cecil is a freelancer writer specializing in technology. He has been a freelance writer for three years and has published extensively on, writing articles on subjects as diverse as boat motors and hydroponic gardening. Van Cecil has a Bachelor of Arts in liberal arts from Baldwin-Wallace College.