After a long Indiana winter, the temptation to fire up the mower the first time you see green is hard to resist. But timing matters. Mowing too early can stress your lawn when it is still waking up. Wait too long and the grass gets ahead of you. Here is how to get the first mow right.
Watch the Grass, Not the Calendar
There is no magic date for the first mow in Fort Wayne or Marion. Some years the grass starts growing in late March. Other years it does not really get moving until mid-April. It all depends on soil temperature and moisture.
Purdue Extension's Maintenance Calendar for Indiana Lawns (AY-27-W) says to begin mowing when the lawn greens up and starts actively growing. That is the key: active growth, not just a little bit of green. You want to see the grass blades actually getting taller over a few days.
For most of northeast Indiana, the first mow usually falls somewhere between the second and fourth week of April. But in a warm spring, it could be earlier. In a cold spring, later.
The Right Height for the First Cut
For that first mow, set your mower to about 2.5 to 3 inches. This is slightly lower than where you will keep it for most of the summer (3 to 3.5 inches), and there is a reason for that.
The first cut cleans up dead blade tips left over from winter. It removes brown, dry material and exposes the green growth underneath. It also gets air circulating at the turf surface, which helps the soil dry out and warm up faster.
Purdue Extension recommends maintaining cool-season grasses at 2.5 to 3.5 inches through the growing season (AY-7-W). Starting at the lower end for the first cut, then raising the deck as summer approaches, is standard practice.
Do Not Scalp the Lawn
Some homeowners drop the mower deck as low as it will go for the first mow, thinking they are cleaning things up. This is called scalping, and it is one of the worst things you can do in spring.
Scalping removes too much of the grass plant at once. Purdue's general rule is to never cut more than one-third of the grass blade height in a single mowing. If the grass is 4 inches tall, cut it down to about 3 inches. If it has gotten away from you and is 6 inches tall, cut it to 4 inches, then bring it down to your target height a few days later.
Scalping also exposes bare soil to sunlight, which is exactly what crabgrass seeds are waiting for. Ohio State Extension warns that scalped areas are prime real estate for weed invasion because the open soil lets weed seeds germinate faster.
Sharpen Your Blade First
Before that first mow, take the blade off and sharpen it. If you did not sharpen it at the end of last season, it has been sitting all winter and is definitely dull.
A dull blade tears the grass instead of cutting it cleanly. The torn tips turn white or brown, making the lawn look hazy and stressed. Torn blades also dry out faster and are more vulnerable to disease. Purdue Extension recommends sharpening mower blades four to six times per season for a clean, healthy cut.
You can sharpen a blade yourself with a file or bench grinder, or drop it off at most hardware stores. A spare blade is a good investment so you can rotate them without downtime.
Check These Before Your First Mow
Is the ground firm enough? Michigan State Extension warns that mowing on soft, saturated soil causes compaction and ruts. If your shoes are sinking in, wait a few more days for the ground to firm up.
Is the grass dry? Mowing wet grass leads to uneven cuts, clumping, and can spread disease. Wait until the dew has dried or until an afternoon dry spell.
Have you done spring cleanup? Clear sticks, leaves, and debris before mowing. Running over debris can damage your blade and scatter junk across the lawn.
Is your mower ready? Fresh oil, clean air filter, good spark plug, and a full tank of fresh gas. Old gas from last fall can gum up a carburetor. Iowa State Extension recommends a quick mower tune-up each spring as part of your lawn care routine.
What About the Clippings?
Leave them on the lawn. Grass clippings break down quickly and return nitrogen and other nutrients to the soil. Purdue Extension's guide on mowing (AY-7-W) confirms that clippings do not cause thatch buildup and actually reduce the amount of fertilizer your lawn needs over a season.
The only exception is if the grass got really long and the clippings form thick clumps that smother the turf underneath. In that case, either rake up the clumps or mow over them again to break them up.
Set a Rhythm Early
Once you start mowing, try to keep a regular schedule. During spring's peak growth (late April through May in our area), you may need to mow every 5 to 7 days. That sounds like a lot, but it is easier on the grass than letting it grow tall and then cutting off too much at once.
Consistent mowing encourages the grass to spread sideways and fill in thin spots. It also keeps weeds from getting tall enough to produce seed heads. A thick, regularly mowed lawn is your best defense against weeds, which is exactly what Purdue's weed management publications recommend as the first line of control.