The Effects of Sugar on Grass

Nitrogen

• Understanding how the plants take up nutrition from the soil is important to understanding the effects of sugar on grass. Bacteria and other micro fauna in soil are busy converting nitrogen in the soil to a form of ammonia during warm weather and when the soil is moist. They use the carbon in the soil for food, and the nitrogen for energy. When the bacteria die, this ammonia is available to the plant roots to take up as a vital nutrient needed for plant growth.

Microbe Growth

• More organic material in the soil gives the bacteria more access to carbon, which allows them to multiply faster and ties up the available nitrogen in their growth. Putting sugar into the soil is like providing a banquet to a group of starving people. The microbes use the excessive amount of carbon in the sugar to go on an unrestrained growth binge. As a consequence, the bacteria uses much of the nitrogen in the soil all at once, which means that less is available for a later time, thus starving the grass.

Experimenting

• Professor Jeff Gillman, in his book "The Truth About Garden Remedies: What Works, What Doesn't, And Why," relates his experiment of adding sugar to soil around plants to see what would happen. He reports that the microbes in the soil around the roots did multiply rapidly, but that the plants that did not receive any sugar actually performed better.

Compost Tea

• Compost tea, or the mixing of mature compost with water to produce an environment where microbes can freely multiply, often uses a form of sugar as one of the ingredients. Molasses is a favored approach and does do the job of giving a jump start to bacteria growth. The tea is often diluted with water on anywhere from a 1:1 to 1:10 ratio and then used to water plants and lawns. The idea behind compost tea is to provide a larger population of microbes, along with a proper ratio of extra carbon and nitrogen, to the soil so the microbes can create more nutrients for the plants.