Those wonderful green lawns many homeowners care about so much can be made much more healthy if we put them on a diet. Overfeeding causes as many problems with lawns as it does with people. Fat lawns are not healthy lawns. Rather than go on about this problem, let me simply tell you about the research at the University of Guelph.
Researcher Christopher Hallfound there was a way to promote health in the lawn by the frequency of the fertilizer application and the amount of fertilizer applied. According the Hall, fertilizer for lawns should be applied three times per year. One quarter of the fertilizer being applied should be applied in early summer, (not early spring) when the ground warms up and the grass is beginning to really grow. Another quarter is applied in late summer, around the middle of August when the fall rains are promoting growth, and the last half of the fertilizer is applied at the end of November to fatten up the roots for winter survival. This application rate was found to create a much denser turf than applications at other times all species and cultivars of grass. It was particularly effective on perennial rye grass and tall fescues.
The next question is how much food does the lawn need? Chris Hall at Guelph found that the turf did better if only 2 pounds of Nitrogen per 1000 square feet was used over the whole season. From the above paragraph, it can be seen that 1/4 pound is applied in early summer, 1/4 pound in late summer and 1 full pound in late November for the healthiest, thickest lawn.
Overfeeding produces thatch and weakened grass that is susceptible to pests and disease. It is also more costly. So, put your lawn on a diet for a better lawn.