Three weeks ago, many turfgrasses began greening up as surface soil temperatures warmed into the 50s °F during the day. Currently, surface soil temperatures are reaching into the 60s °F during the day, which stimulates vertical leaf growth especially after a rain. Any early spring N fertilization will also encourage vertical leaf growth.
Accordingly, mowing equipment should be reconditioned and ready for routine use. Setup of mowing height should not be overlooked; an incorrect mowing height will lead to problems. Generally, lawn grasses will be easier to maintained at a mowing height of 3-inches or higher.
Grasses will be healthier when there are more leaves (leaf area) to capture sunlight for photosynthesis and shade the soil surface. More photosynthesis helps the grass grow more roots and a shaded soil surface remains cooler. Shade also blocks the exposure of weed seed to light, which is an environmental trigger for weed germination.
Uneven ground is another reason to recommend relatively high mowing. Many lawns are relatively uneven. A lack of smoothness in a lawn contributes to poor mowing. A mower set 3-inches helps protect high spots in a lawn from being severely scalped. For example, a high spot in a lawn that ends up being cut at 2-inches with a mower set at 3-inches would be cut at 1-inch if the mower were set at 2-inches.