The timing of the first lawn mow after a Michigan winter significantly impacts the long-term health of the turf. Michigan’s variable climate hosts predominantly cool-season grasses, such as Kentucky Bluegrass. Transitioning the lawn out of winter dormancy requires careful observation rather than relying on a calendar date. Starting the mowing process too early or too late can stress the grass, making it vulnerable to disease and weed invasion. The goal is to initiate spring care when the grass begins its active growth cycle.
Reading the Lawn: Indicators for the First Cut
Determining the exact moment to start mowing is based entirely on biological and environmental cues. Cool-season grasses begin actively growing once the soil temperature consistently stabilizes above 40 to 45 degrees Fahrenheit. This soil warmth indicates that the grass roots are emerging from dormancy. The most practical sign that the first cut is due is the grass blade height itself. Wait until the turf reaches approximately three to four inches before mowing. This waiting period ensures the grass has sufficient leaf surface area to support the root system before any of the blade is removed.
Essential Preparation Before Mowing
Before the mower blade turns for the first time, several preparatory steps are necessary to protect the turf and the equipment. Start by clearing the lawn of all winter debris, including fallen branches, sticks, and matted leaf litter. Raking away this debris prevents damage to the mower and allows light and air to reach the grass crown. Ensure the ground is dry enough to support your weight and the equipment. Mowing on wet turf leads to significant soil compaction, restricts oxygen flow to the roots, and can create unsightly ruts.
Equipment readiness should not be overlooked, starting with the mower blade. Using a freshly sharpened blade is paramount, as a dull edge tears the grass blades, leaving jagged wounds that turn white or brown. These rough cuts increase the plant’s susceptibility to disease and require more energy for the grass to heal. Performing basic maintenance, such as checking the oil and spark plug, ensures the machine runs efficiently for the busy season ahead.
Technique for the First Mow of the Season
The cutting technique for the first mow differs from the regular summer routine. It must adhere strictly to the “one-third rule,” meaning no more than one-third of the grass blade’s total height should be removed in a single pass. For example, if the grass is four inches tall, cut it down to around 2.6 inches. Setting the mower deck slightly lower than your typical summer height is advised, aiming for a finished height of about 2.5 to 3 inches. This lower cut removes brown, winter-damaged tips and stimulates the turf to grow horizontally, encouraging a denser canopy.
Scalping the lawn by cutting too short must be avoided, as it stresses the plant and exposes the soil to sunlight. If the clippings are short and dispersed, leave them on the lawn to recycle nutrients back into the soil. These fine clippings, known as grass cycling, do not contribute to thatch buildup and act as a natural fertilizer. Only bag the clippings if the grass was excessively long and the removed material creates heavy clumps that could smother the healthy turf beneath.
Establishing a Healthy Mowing Schedule
Once the first cut is complete, establish a consistent schedule to maintain turf health throughout the spring. Mowing frequency should be dictated by the grass growth rate, not a rigid calendar date. Typically, the lawn requires weekly attention to consistently follow the one-third rule, promoting a dense, uniform stand of grass. The initial mow often coincides with other important spring treatments, such as the application of pre-emergent herbicides. This product is best applied when soil temperatures reach 50 to 55 degrees Fahrenheit for several consecutive days, which is the perfect window to stop crabgrass seeds from germinating. A light, balanced spring fertilization can also be applied around this time.