What is the proper mowing height for shady turfgrass areas?
Do not mow shady areas less than 3 inches in height. Because of the lower photosynthetic rates in shady areas, the turfgrass plants need a large leaf surface to manufacture adequate amounts of food. The recommended mowing height for grass growing in shady areas is 3 to 3½ inches. (A 3 to 3½ inch mowing height is also fine for sunny areas.)
When mowing turf, never remove more than 1/3 of the total leaf surface at any one time. If the mower is set at 3 inches, cut the grass when it reaches a height of 4½ inches.
If possible, alternate the mowing direction from one mowing to the next. Mowing the lawn in the same direction or pattern may damage certain areas. The damage is caused by the mower wheels repeatedly going over the same areas, resulting in soil compaction and physical wear.