Can Fertilizers Burn Your Grass?
- Nitrogen is applied to grass to promote dense growth and chlorophyll production, which keeps your grass green. The nitrogen that is in fertilizers is in urea form, according to Rutgers University. When too high of a percentage or too much nitrogen is applied to lawns, grass dehydrates. Grass will also dehydrate if the nitrogen has been applied without watering the chemicals in after the fertilizer application or on a hot day. Noticing the signs of nitrogen burn helps prevent future problems.
- Gardeners may see brown spots or patches develop on their lawns after fertilizing. Brown patches are often irregular in shape. These brown areas indicate dead, dried-up grass. Sometimes, brown patches of grass can be misdiagnosed as a fungal disease problem. Brown patch is a fungal disease that causes brown grass. However, brown patch disease will produce a circular patch on the lawn that often has a black band around the perimeter of the patch, according to Purdue University.
- Prevent burning your grass by applying the right amount of nitrogen to the yard. Grass generally needs 1 lb. of nitrogen per 1,000 square feet, according to the University of Illinois. Applying more than that can result in fertilizer burn. When applying nitrogen, make sure that your rotary spreader evenly spreads the fertilizer over the yard. Broken fertilizer spreaders apply too much nitrogen in some areas, which will lead to grass burning.
- Avoid applying fertilizers on hot days or to water stressed lawns. Water your lawn for several days prior to fertilizing. Apply 1 inch of water to the lawn after spreading the fertilizer. You can also fertilize your lawn in the morning to save water. Lawns typically need to be fertilized with a slow-release fertilizer every six weeks during the growing season. Stop fertilizing when your grass is at the end of its growing season.