Grasscycling: Stop Bagging Your Grass Clippings
Leaving the clippings on the lawn is less work, feeds the grass for free and means no more heavy bags. Here's how to do it without clumps.
- Take the bag off the mower and let clippings fall.
- Mow when the grass is dry.
- Never cut more than one-third of the blade height at once.
- Raise the mower deck a notch and keep the blade sharp.
- Mow more often when the grass is growing fast.
- Blow or sweep clippings off pavement back onto the lawn.
Bagging grass clippings is one of those chores people do because they've always done it. Stop the mower, unclip the heavy bag, haul it to the bin, clip it back on, repeat. Drag the bin to the curb. Then maybe buy fertilizer to put back what you just threw away.
There's an easier way, and it has a name: grasscycling. You leave the clippings on the lawn, where they break down and feed the grass. It's free, it's faster, and it's standard advice from university extension services. Here's the free way first. After that there's an optional upgrade box with two tools that make it even easier. Buying them is optional.
Why grasscycling is worth it
Less work. No stopping to empty the bag, no hauling, no stuffing yard waste bags. Mowing simply gets faster.
Free fertilizer. Clippings break down quickly and return nutrients, including nitrogen, to the soil. That can cut how much fertilizer your lawn needs from a bag.
Less yard waste. Your bin stays lighter, and you stop paying in bags, fees or trips to send away something your lawn can use.
The big myth: "Clippings cause thatch"
This is why a lot of people keep bagging, and it's a myth. According to university extension services, grass clippings don't cause thatch. Thatch, the spongy layer that can build up between the grass and the soil, is mostly stems and roots, which break down slowly. Clippings are soft and break down fast.
What clippings can do is clump and smother the grass if you cut too much at once or mow a wet lawn. The steps below prevent that.
The free way, step by step
Step 1: Take the bag off
Remove the bag or grass catcher and switch to your mower's mulching or side-discharge setup. Many mowers come with a mulching plug or cover that closes the bagging chute; check your manual. If yours side-discharges, aim the chute toward the lawn, not the sidewalk, the flower beds or your neighbor's car.
Safety note: Use only the mulching or discharge setups your manual describes. Before reaching anywhere near the blade or clearing a clog, turn the mower off and let the blade stop; on gas mowers, disconnect the spark plug wire, and on electric ones, remove the battery or unplug the cord.
Step 2: Mow when the grass is dry
Wet grass clumps. Wet clippings mat on top of the lawn instead of filtering down to the soil, and they clog the mower deck. Wait until the dew dries or a day after rain. Late morning or early evening is usually ideal, and easier on you than the midday heat.
Step 3: Follow the one-third rule
This is the most important habit. University extension services consistently advise never cutting more than one-third of the grass blade's height in a single mowing.
In practice, decide what height you want, set the mower deck there, and mow before the grass grows much past it. Let it get far taller than your target and a single pass takes off too much. Then two things happen: the long, heavy clippings clump and smother the grass, and the lawn is stressed from losing too much leaf at once. Stick to the rule and clippings are short enough to slip down between the blades and disappear within days.
Tip: If the lawn got away from you during a vacation or a rainy stretch, don't fix it in one pass. Raise the deck, take off the top third, wait a few days, then lower the deck and cut again. Two easy passes beat one scalping.
Step 4: Mow a bit higher
Raise your mower deck a notch or two. Taller grass shades the soil, which helps it hold moisture and makes it harder for weed seeds to sprout, and taller blades tend to support deeper roots. The right height depends on your grass type and region, so check with your local extension service. For keeping a lawn going through hot, dry stretches, see our guide to watering during a heat wave.
Step 5: Keep the blade sharp
A dull blade tears grass instead of cutting it, leaving ragged, brown tips that make the lawn look tired. A sharp blade cuts clean and leaves smaller clippings that break down faster. Check the blade at the start of the season and again midway through. If the tips look shredded a day after mowing, it's time. Many hardware stores and small-engine shops will sharpen a blade, or you can do it yourself with a file, following your manual for removing it safely. Wear heavy gloves, and check that the blade still balances before you put it back, since an unbalanced blade shakes the mower.
Step 6: Mow more often when the grass grows fast
Grass grows fastest in its peak season (spring and fall for cool-season lawns like bluegrass and fescue, summer for warm-season lawns like Bermuda and zoysia) and during wet stretches. To stick to the one-third rule, mow more often during those weeks. Each mow is quicker with no bag to empty and no heavy clumps to fight. When growth slows, you can mow less often.
Step 7: Keep clippings off the pavement
Clippings on the lawn are fertilizer. Clippings on the street are a problem. Grass on sidewalks, driveways and streets can wash into storm drains, which often carry rainwater straight to local creeks and lakes without treatment. When you finish, blow or sweep clippings off the pavement back onto the lawn, and aim the discharge toward the grass when you mow along edges.
Troubleshooting
- Clumps or rows of clippings. The grass was too wet, too long or both. Rake the clumps out so they dry and filter down, and mow more often next time.
- Brown, ragged tips. Dull blade. Sharpen or replace it.
- Mower keeps clogging. Wet grass or too much growth. Let it dry, raise the deck and take off less per pass.
- Thick, spongy thatch. Clippings aren't the cause. Ask your local extension service about core aeration or dethatching.
- Diseased patches. Ask your extension service whether to bag clippings from that area until it clears up.
Small yard or a rental?
Grasscycling works on any size lawn, and it's a good fit for renters who handle the mowing but don't want to haul bags. If you've been thinking about shrinking the lawn altogether, swapping part of it for native plants means less mowing and a yard that's friendlier to bees and butterflies.
When the upgrade is worth it (and when it isn't)
A push reel mower is worth it for small, flat lawns. It's quiet, needs no gas or charging, and its scissor-like cut leaves fine clippings that disappear fast. It's a poor fit for large lawns, rough or hilly ground, or grass you let get tall, since reel mowers struggle with long grass and twigs.
A blade sharpener is worth it if you mow a lot. If you mow often over a long season, sharpening at home saves trips to the shop. If a shop sharpens your blade once a season, that's fine too.
Happy with your current mower? You don't need either tool. Take the bag off and you're already grasscycling.
The short version
Take the bag off. Mow when the lawn is dry, never cut more than one-third at once, set the deck a little higher and keep the blade sharp. Sweep stray clippings off the pavement back onto the grass. You'll do less work, spend less on fertilizer and send nothing to the curb.
Common questions
Is it better to bag or leave grass clippings?
For most lawns, leave them. Clippings break down quickly and return nutrients, including nitrogen, to the soil, so you're feeding the grass for free. It's also less work than emptying a bag. The exceptions are very long or wet clippings that clump, and clippings from diseased patches, which your local extension service may suggest removing.
Do grass clippings cause thatch?
No. According to university extension services, clippings don't cause thatch. Thatch is mostly made of stems and roots, which break down slowly. Clippings are soft and break down fast. If you have a thick thatch layer, something else is going on, and your local extension service can suggest aeration or dethatching.
What is the one-third rule for mowing?
It's standard extension advice: never cut off more than one-third of the grass blade's height in one mowing. In practice, set the deck at the height you want and mow before the grass grows much past it. Following the rule keeps clippings short enough to filter down to the soil instead of clumping, and it's less stressful for the grass.
Can you grasscycle with a regular mower?
Yes. Take off the bag and use the mulching setting or plug if your mower has one, or the side-discharge chute pointed toward the lawn. A dedicated mulching mower or blade chops clippings finer, but any mower works if you mow dry grass, follow the one-third rule and keep the blade sharp.
How do you keep grass clippings from clumping?
Mow when the grass is dry, never take off more than one-third of the height at once, and mow more often when the grass is growing fast. A sharp blade helps too. If clumps do form, spread them out with a rake so they can dry and settle between the grass blades.