Grass Height is very important when maintaining a healthy lawn. Some people like very short grass, but this is very bad for cool season lawn grasses (Tall Fescues, Kentucky Blue Grass, and Perennial Rye Grass). Cutting your lawn short is very unhealthy for your grass because it increases the chance of weeds, turf diseases, and harmful insects. Cutting the grass short will cause the grass to be sparse. These sparse areas will quickly fill with weeds. Most weeds grow much faster than grass and would therefore need to be mowed more often than a healthy lawn. Under our lawn care program grass is cut about 2 3/4 to 3 inches tall and should be cut before it is 4 to 4 1/2 inches tall. The taller grass blade will shade the ground and make it more difficult for the weed seeds to germinate. The longer blade of grass will be able to receive more light, and the proceess of photosynthesis will be more effective, thereby causing a healthier plant. A healthy plant has a more mature root system, which will not only help the plant to be healthy, but will crowd out the competition (weeds from developing).
Let the land produce vegetation...And God saw that it was good.