Though lawns in southern Indiana may have already been mowed a couple of times, mowing is just starting from Indianapolis north. Mowing is the most expensive and laborious maintenance practice on turf, but it also has the largest effect on long-term performance:
It is better to mow too early rather than too late in the spring and most of us tend to mow too late. Grass grows from the bottom of the leaf pushing last year’s dead brown tissue to the leaf tip. Even though the lawn still appears fairly brown from above, it is actively growing and probably needs mowing before you realize it.
Set your mower as high as feasible. Mowing at 3” or higher is the best way to maintain a healthy lawn. On a concrete surface, measure from the concrete to the actual blade tip (not the housing). Or simply use the highest setting for most mowers.
You cannot mow too often especially in the spring. You should mow often enough not to remove more than 1/3 of the leaf blade. So if you’re mower is set to 3”, you should mow when the turf reaches about 4.5”, preferably earlier. This might require mowing every 4 to 5 days in the spring but every 14 days in the summer. Perennial ryegrass and turf-type tall fescue grow faster in the spring requiring more frequent mowing than Kentucky bluegrass. Mowing more than 1/3 of the leaf blade robs the plant of long-term storage products, making it harder for the plant to perform during the summer heat and drought.
Like knives and power tools, your mower blade cannot be too sharp. Sharp blade creates a clean cut which is more attractive and heals faster than that produced by a dull blade. Plus a sharp blade allows the engine to work less, which is better for the environment. Depending on how much you mow, blades should be sharpened almost daily for professional mowers to every other month for home owners.
Return the clippings, period. Catching the clippings requires more time and effort, steals nutrients from the soil, and has no effect on thatch. I might bend on catching the clippings once or twice per year when the spring rains played havoc on your mowing schedule and/or you are using them for mulch around the garden (not if broadleaf herbicides have been applied recently).
Zac Reicher, Professor/Turfgrass Extension Specialist
Send corrections, suggestions, and comments to biehlj@purdue.edu