July 8, 2023 ยท Lawn Mowing
If you're bagging your grass clippings after every mow, you're doing extra work for worse results. That's not an opinion. It's what the research shows and what we see on properties across Hamilton County every week.
Here's why you should leave the clippings on the lawn and what actually happens when you do.
Clippings Are Free Fertilizer
Grass clippings are roughly 80% water and 4% nitrogen by weight. When you mow and leave the clippings on the lawn, that nitrogen gets recycled back into the soil as the clippings decompose. Over the course of a full mowing season, this returns the equivalent of one to two full fertilizer applications worth of nitrogen to your lawn for free.
That's real money. If a fertilizer treatment costs $50 to $80, you're saving $50 to $160 per year in fertilizer value just by not bagging. And the nutrients are released slowly as the clippings decompose, which is actually better for the grass than a single concentrated application.
Clippings Do NOT Cause Thatch
This is the biggest myth in lawn care. Many homeowners bag because they believe clippings cause thatch buildup. They don't.
Thatch is a layer of dead roots, stems, and stolons that accumulates between the grass blades and the soil surface. It's made of fibrous plant material that resists decomposition. Grass clippings are mostly water and soft tissue. They break down within days, not weeks. They decompose far too quickly to contribute to thatch.
Thatch is caused by aggressive growth from over-fertilization, certain grass varieties that produce heavy stolon growth, and acidic soil conditions that slow microbial decomposition. Core aeration is the solution for thatch, not bagging.
When Clippings Look Bad (and What to Do)
The one situation where clippings look messy is when the grass gets too tall between mowings and you're cutting off large amounts at once. Long clippings sit on top of the lawn in clumps instead of falling between the blades. This looks bad and can smother the grass underneath the clumps.
The fix isn't bagging. The fix is mowing more frequently. If you follow the one-third rule (never cutting more than one-third of the blade height per mow) and mow weekly, the clippings are short enough to fall between the blades and disappear within a day or two.
If you do miss a week and the grass is overgrown, mow it in stages rather than scalping it down in one pass. Take off the top third, wait a few days, then bring it down to target height. The shorter clippings from each pass will disappear on their own.
Bagging Wastes Time and Money
Bagging adds 20-30% more time to every mow session because you're stopping to empty the bagger, and it fills up fast during peak growing season. Those bags of clippings then need to go somewhere: either to the curb for municipal pickup, to a composting area, or to the landfill. It's labor and disposal cost for something that was better off staying on the lawn in the first place.
The Exception: Diseased Lawns
The one legitimate reason to bag clippings is when your lawn has an active fungal disease. Some diseases (like brown patch and dollar spot) can spread via infected clippings being distributed across the lawn by the mower. If you're dealing with an active infection, bagging temporarily prevents redistribution while the disease is being treated. Once the infection clears, go back to mulching.
What We Do
At Sprout Lawn & Landscape, we mulch clippings on every property unless there's a specific reason not to (like active fungal disease where removing infected material helps stop the spread). Our commercial mowers have mulching blades that cut clippings into fine pieces that decompose quickly. Combined with weekly mowing at the right height, you never see clipping clumps on the lawn after we leave.
We serve Noblesville, Carmel, Westfield, Fishers, and surrounding Hamilton County communities. Learn more about our mowing service or get instant pricing.