What to Do With Grass Clippings: State Landfill Bans and Nitrogen Math

What to do with grass clippings also turns on a legal question most guides skip. We read the rule in 25 states that restrict yard waste or require its collection: 21 reach clippings in some form, 5 of those let a landfill with a gas or energy system take them, and Indiana, New Jersey and Pennsylvania leave grass out of their bans. The Rutgers trial supplies the rest of the answer: about 1,140 lb of fresh clippings a year off a 5,000 sq ft lawn, holding $15 to $31 of nitrogen.

What to do with grass clippings: 9 options and the limit on each

Option	Use it when	The limit	Source
Leave on the lawn	Lawn is dry and healthy	Clippings 1 inch or shorter; cut no more than 1/3 of the blade	UMN Extension
Bag one cut, then go back to returning	You missed a mowing or two in wet weather or a growth surge	Resume once the grass is under control	Oregon State
Mulch beds and gardens	Clippings are dry and the lawn was not recently treated	1 to 2 inches at one time	UMN Extension
Backyard compost	You have dry leaves or straw to mix in	About 6.8 lb dry leaves per 10 lb fresh grass	Cornell
Yard-waste cart or compost site	Your town collects it or you can haul it	No trash mixed in; bag type can be regulated	Minn. Stat. 115A.931
Household trash	State and town allow it	Check the state table: fine in Indiana, barred in Wisconsin	IDEM; Wisconsin DNR
Over the fence to livestock	Not advised	Colic risk in horses; wet piles can mold and ferment in warm weather	Penn State
Burn	Check your state first	Nebraska says grass clippings cannot be burned at its community burn sites	Nebraska DWEE
Woods, street or storm drain	Not on land you do not own	36 CFR 261.11(e) on National Forest land; up to $50 in Dyer, Tenn.	eCFR; City of Dyer

Start with the first row, because it is the only option that adds no work. Mowing on the one-third rule keeps clippings short enough to use it: University of Minnesota turf scientist Jon Trappe works the example of a 3-inch lawn cut at 4.5 inches, about every 7 days in Minnesota, against a 4-inch lawn cut at 6 inches, every 10 to 12 days. Our guide on how often to mow your lawn covers the schedule.

1. 1Will clippings be longer than 1 inch, or are you cutting more than 1/3 of the blade?

   YesBag or rake this cut, or mow down in stages a few days apart (UMN).

   NoGo to the next question

2. 2Is the grass wet enough that clippings clump or mat?

   YesBag this cut or wait; mats smother the grass beneath (UMN, Oregon State).

   NoGo to the next question

3. 3Is leaf spot, rust or dollar spot heavy in the lawn?

   YesBag until it clears to reduce disease severity (UMN).

   NoGo to the next question

4. 4Was weed killer applied since your last 3 mowings?

   YesLeave clippings on the lawn. Do not mulch or compost them until the label allows it.

   NoGo to the next question

5. 5Are clippings landing on a street, sidewalk or gutter?

   YesBlow or sweep them back onto the lawn; many cities fine this (UMN, Dyer, Tenn.).

   NoLeave them on the lawn. Weeds and thatch are not reasons to bag (UMN, Penn State).

Source: UMN Extension, What to do with lawn clippings

How much nitrogen do clippings return?

About 1 to 2 lb of nitrogen per 1,000 sq ft a year on a lawn fed 2 lb. That figure comes from a four-year Rutgers trial on irrigated Kentucky bluegrass, which weighed clipping yield at three fertilizer rates and scored color on a 1 to 10 scale. Rutgers assumed 38 lb of dry clippings and tissue nitrogen of 2.5 to 5.1 percent. Clippings are about 85 percent water, so it multiplies dry weight by 6 to get fresh weight.

Nitrogen applied (lb per 1,000 sq ft a year)	Dry clippings (lb)	Fresh clippings at x6 (lb)	Color, clippings removed	Color, clippings returned
0	23	138	3.2	5.2
2	38	228	5.5	6.9
4	58	348	6.4	7.7

1. 0 lb N3.20
2. 2 lb N5.50
3. 4 lb N6.40

Source: Rutgers Cooperative Extension, The Soil Profile, Spring 1999, Table 1 Season average on a 1 to 10 scale, where 10 is dark green. Nitrogen in lb per 1,000 sq ft a year. Irrigated Kentucky bluegrass.

Show the numbers

	Clippings removed	Clippings returned
0 lb N	3.20	5.20
2 lb N	5.50	6.90
4 lb N	6.40	7.70

Read across the 2 lb and 4 lb rows. Returning clippings at 2 lb scored 6.9, while removing them at twice the fertilizer scored 6.4. Half the nitrogen with clippings beat double the nitrogen without them on the season average, although the 4 lb plots looked better in May alone.

Other research lands in the same place. The two-year Connecticut study by Kopp and Guillard (2002), run on a cool-season mixture at rates up to 392 kg of nitrogen per hectare, found fertilizer could drop 50 percent or more with no loss of quality. Extension figures are more cautious, from 20 percent up.

Source	Setting	What it found
Kopp and Guillard, Crop Science 42:1225	Storrs, Conn., 1998 to 1999, cool-season mix	Returning clippings raised dry yield 30 to 72 percent and nitrogen uptake 48 to 60 percent; fertilizer could fall 50 percent or more
Penn State Extension, updated Oct. 2025	Kentucky bluegrass, 3 years	Clippings held 46 to 59 percent of the nitrogen applied as fertilizer
Trappe, University of Minnesota, 2019	Minnesota lawns	Removing clippings takes away up to 2.0 lb of nitrogen per 1,000 sq ft a year
Oregon State Extension, reviewed 2025	Oregon State research	Clippings run up to 3 to 4 percent N, 0.5 percent P, 2.5 to 3.5 percent K; fertilizer can fall almost by half
Purdue AY-22-W, 2013	Indiana cool-season lawns	If you must remove clippings regularly, annual nitrogen may need to rise 25 to 50 percent
NC State Extension Gardener Handbook, ch. 9	North Carolina lawns	Fertilizer use can fall 20 to 30 percent; studies show 1,000 sq ft can produce 500 lb of clippings in a growing season

The trial numbers are cool-season, so treat them as direction, not a figure, on bermudagrass or St. Augustine. NC State, writing for a state with both, says to catch or rake clippings only when they are heavy enough to hold the grass down or shade it. For the nitrogen you still need after returning clippings, see how to add nitrogen to lawn soil and the product prices in our lawn fertilizer guide.

The math on a 5,000 sq ft lawn

Step	Arithmetic	Result
Dry clippings a year, 2 lb N program	38 lb per 1,000 sq ft x 5	190 lb
Fresh weight to bag and haul	190 lb x 6	1,140 lb
Nitrogen inside them	190 lb x 2.5 to 5.1 percent	4.75 to 9.7 lb
Value at the cheapest bag in our fertilizer guide	$3.17 per lb of N	$15 to $31
Value at the priciest of the 4 bags in the calculator	$10.40 per lb of N	$49 to $101

Lawn area (sq ft)Fertilizer you would otherwise buy (October 2026 price per lb of N)Scotts Turf Builder 38-0-4, 37.9 lb, $3.17 per lb NPennington Full Season 32-0-5, 33.6 lb, $4.67 per lb NEspoma Lawn Food 15-0-5, 40 lb, $8.33 per lb NMilorganite 6-4-0, 32 lb, $10.40 per lb NNitrogen you apply each year (lb per 1,000 sq ft)2 lb4 lbNone

Fresh clippings a year (lb)

1,140

Nitrogen, low estimate (lb)

4.8

Nitrogen, high estimate (lb)

9.7

Fertilizer value of that nitrogen$15 to $30

Default: 5,000 sq ft at 2 lb N: 1,140 lb fresh, 4.8 to 9.7 lb of nitrogen, about $15 to $30 at $3.17 per lb N (rounded to $5). Yields are Rutgers' irrigated Kentucky bluegrass; tissue nitrogen of 2.5 to 5.1 percent is assumed at every rate. Estimate, nitrogen only.

The fertilizer saving is real but small: under 10 lb of nitrogen a year on this lawn. The weight is the larger argument. Moving more than half a ton of wet grass is what returning clippings spares you, and homeowners on Texas A&M AgriLife's Don't Bag It plan report mowing in 38 percent less time, a self-reported figure.

Is it better to mulch or bag grass?

Mulch by default and bag in the three cases UMN Extension names: leaf spot, rust or dollar spot is heavy; the grass is wet or too tall and clippings mat; or the mower is unsafe without its bag attached. Add one more from the same page: sweep clippings off curbs and gutters so they stay out of storm drains. Our pages on lawn fungus and mowing wet grass cover those two cases in depth.

Two common reasons to bag do not hold up. Weeds first: Trappe calls it a misconception, since seeds already in the soil stay viable for years or decades, and Rutgers counted significantly fewer August weeds where clippings were returned, in plots that also received preemergence herbicide each spring. Thatch second: Penn State says leaf tissue decomposes rapidly and does not contribute, and UMN blames vigorous varieties, excess nitrogen, infrequent mowing and low soil oxygen instead. If thatch tops 1/2 inch, the fix is in how to dethatch a lawn.

Do you need a mulching mower or kit?

No. Rutgers states that mulching mowers are not required and conventional rotary mowers also work, though its returned plots used a mulching mower. A kit chops finer, which Penn State says speeds decomposition. Oregon State puts blade sharpening at every 20 to 25 hours of use, and our blade sharpening guide shows how.

Mower	Kit	What the maker lists	Price checked Nov. 5, 2026
Most Cub Cadet, Craftsman and Troy-Bilt 42-inch riders, 2015 on	19A70041GFP	2 mulching blades, baffle, hardware	From $74.19 MSRP
John Deere 42A deck	BUC11053 MulchControl	Lever-operated baffle; side discharge mode still mulches about one third of the material	No price shown to us
Toro TimeCutter 42-inch fabricated deck	139-3265 Recycler kit; manual	2 mulching blades, baffle, decal, per the install manual	No price shown to us

Can you use clippings from a lawn treated with weed killer?

Return them to the lawn, and read the label before they go anywhere else. The label is the law, and wording differs by product: of the 5 labels below, 2 name 3 mowings, 2 set no end date and 1 is silent. UMN Extension says not to mulch with clippings from a lawn recently treated for dandelions or other broadleaf weeds, and gives no day count.

Product and EPA Reg. No.	Active ingredients	What the label says about clippings
Lawn Herbicide 3F Concentrate, 92564-34	2,4-D, mecoprop-p, dicamba, fenoxaprop-p-ethyl	“Leave grass clippings on the lawn from the first 3 mowings after using this product. Do not use as compost or mulch.” Bracketed as optional label text
Spectracide Weed Stop for Lawns Plus Crabgrass Killer, 9688-337-8845 (Reg. No. from a posted copy of the maker’s SDS)	2,4-D, quinclorac, dicamba, sulfentrazone	“Clippings from the first three mowings should be left on the treated area,” and not used as mulch or compost around flowers, ornamentals or trees, or in vegetable gardens
Solitare, 101563-310	Sulfentrazone, quinclorac	“Do not use clippings as mulch or compost around flowers, ornamentals, trees or in vegetable gardens.” No end date given
Scotts Turf Builder Weed & Feed, 538-333	2,4-D, dicamba	No mulch or compost line in the 2018 accepted label we read; it says to leave clippings on your lawn
Imprelis (stop-sale order Aug. 2011)	Aminocyclopyrachlor	“Do not use grass clippings from treated areas for mulching or compost, or allow for collection to composting facilities”

The persistent group is the pyridine herbicides aminopyralid, clopyralid and picloram. NC State AG-727 says they can stay active in clippings and compost for anywhere from 30 days to several years, but also that clopyralid products have not been registered for residential lawns since 2002. Golf course and commercial turf clippings are the higher risk, so ask for the product name and EPA Reg. No. before accepting free clippings. If a lawn service treats your turf, ask it the same question. Our lawn weed killer comparison lists the actives by product.

Those same actives come up in forum advice about thistles, though their labels bar home lawns; our page on what kills thistles but not grass lists the lawn labels to use instead.

This page is general information, not legal or pesticide-use advice. The label is the law for any pesticide, and state and local waste rules change; confirm with the agency linked for your state.

How to mulch or compost clippings

To use clippings as garden mulch, follow UMN Extension's conditions in order:

1. Confirm no broadleaf herbicide went on recently, using the label table on this page.
2. Dry the clippings first. Wet layers mat down, cut off oxygen and moisture, and can decompose anaerobically with a foul smell.
3. Spread no more than 1 to 2 inches at one time around vegetables, flowers, shrubs or trees.

Composting is a mix problem. Cornell puts grass at 15 to 25:1 carbon to nitrogen and autumn leaves at 30 to 80:1, against a target near 30:1. Cornell's moisture and C:N worksheets then give two answers for the same 10 kg of grass, and the wetter one is the mistake to avoid.

Leaves added to 10 kg fresh grass	Resulting C:N	Resulting moisture	What happens
3.5 kg	30:1	Over 66 percent	Hits the C:N target, but wet enough to risk anaerobic odor
6.8 kg	A little under 37:1	60 percent	Cornell’s pick: may compost slower, more likely to be trouble free

So weigh in about 7 lb of dry leaves for every 10 lb of fresh grass, the same ratio in any unit, and never add a thick grass-only layer. For scale, Connecticut exempts a leaf-composting facility from certain permits only if it holds at least 3.0 leaves to 1.0 grass clippings (Conn. Gen. Stat. 22a-208i).

Can grass clippings go in the trash? Rules in 25 states

It depends on the state, then the town. Nationally, EPA counted 35.4 million tons of yard trimmings in 2018: 22.3 million composted or mulched, 10.5 million landfilled and 2.6 million combusted. The table sorts each state by what its rule does to a bag of grass, which is often not what a ban list implies.

Swipe the table sideways to see every column.

State	Effect on clippings	Rule	In force	What it says
Arkansas	Reaches clippings, gas or energy exception	Ark. Code 8-6-220	By 1994	Illegal to place yard waste in a facility solely for disposal, beyond fugitive amounts. A landfill with a gas-to-energy system can seek a permit change to accept it.
California	Mandatory collection	SB 1383, CalRecycle	Not dated on the CalRecycle page	Jurisdictions must offer organic waste collection, landscape waste included, unless waived for low population or high elevation. NERC 2020 also lists grass as barred at landfills; we did not confirm that in a statute.
Connecticut	Landfill rule reaches clippings	Conn. Gen. Stat. 22a-208v	After Oct. 1, 1998	Facilities other than composters may not accept “significant quantities of grass clippings.” The section is titled for clippings by name.
Delaware	Landfill rule reaches clippings	DNREC yard waste page	2007	Grass clippings named; banned from all landfills. NERC 2020 reports this as a permit condition at the 3 municipal landfills, not a statute.
Florida	Reaches clippings, gas or energy exception	Fla. Stat. 403.708(12)(c)	By 1994; exception 2010	Barred from lined Class I landfills unless the landfill runs active gas collection with a beneficial use. Incidental amounts are tolerated.
Georgia	Landfill rule reaches clippings	O.C.G.A. 12-8-40.2, Georgia EPD	Sept. 1, 1996	Grass clippings named. Must be separated from trash; barred at lined municipal landfills and vertically expanded landfills, not at every landfill type.
Illinois	Landfill rule reaches clippings	415 ILCS 5/22.22; 5/3.270	July 1, 1990	Grass cuttings are landscape waste. No mixing with trash, and any landfill-bound container must be biodegradable.
Indiana	Grass left out	IC 13-20-9, IDEM	Not dated on the IDEM page	IDEM: the ban “does not apply to: Grass.” Leaves, and brush over 3 ft, stay banned; local ordinances can be stricter.
Iowa	Reaches clippings, gas or energy exception	Iowa Code 455D.9	1991; exception 2015	Cities and counties must require separation. A landfill with a methane system producing energy may accept it, as may storm and pest loads.
Maryland	Only separated loads	Md. Env. 9-1724; NERC 2020	1992	State report to NERC limits the ban to separately collected yard waste, which section 9-1724 routes to organics recycling.
Massachusetts	Landfill rule reaches clippings	310 CMR 19.017	Dec. 31, 1992; transfer stations Apr. 1, 2000	Covers landfills, combustors and transfer stations. UMass counts grass as yard waste; contaminated loads need a DEP permit.
Michigan	Landfill rule reaches clippings	MCL 324.11514; EGLE	1995	No more than a de minimis amount. EGLE: only diseased, infested or invasive-control clippings can be landfilled.
Minnesota	Landfill rule reaches clippings	Minn. Stat. 115A.931; 115A.03	Jan. 1, 1990 metro; Jan. 1, 1992 elsewhere	Lawn cuttings count. In metro counties, plastic bags at compost sites must meet ASTM D6400 unless emptied on the spot.
Missouri	Reaches clippings, gas or energy exception	RSMo 260.250	Jan. 1, 1992; exception Aug. 28, 2007	Allowed only in a state-approved bioreactor whose gas generates electricity.
Nebraska	Reaches clippings, gas or energy exception	Neb. Rev. Stat. 13-2039; state agency	Sept. 1994	Seasonal: municipal landfills may accept it Dec. 1 to Mar. 31. Year-round only with approval for methane fuel, or if separated for composting.
New Hampshire	Landfill rule reaches clippings	RSA 149-M:27, NHDES	1993	Grass clippings named; landfills and incinerators. Dumping in a wetland without a permit is also illegal.
New Jersey	Grass left out	N.J.S.A. 13:1E-99.22	Ordinances due Apr. 20, 1989	The statute covers leaves only. Ewing Township treats grass clippings as solid waste: trash as a last resort.
North Carolina	Landfill rule reaches clippings	G.S. 130A-309.10(f)(3); NC DEQ	By 1994	Yard trash barred except at landfills approved for it, or where separated loads go to on-site composting.
Ohio	Only separated loads	OAC 3745-27-01; Ohio bar	By 1994	Landfills may not accept separated yard waste, yet bags mixed with trash count as commingled. The Ohio bar: you can put yard waste in the trash.
Pennsylvania	Grass left out	25 Pa. Code 271.1; 273.201(j)	By 1994	Bars loads composed primarily of leaf waste, and defines leaf waste as “not including grass clippings.”
South Carolina	Landfill rule reaches clippings	S.C. Code 44-96-190	24 months after the 1991 act	No knowingly mixing yard trash with landfill-bound trash; landfills may not take loads composed primarily of it without on-site composting.
South Dakota	Landfill rule reaches clippings	SDCL 34A-6-67; DANR	1995	No landfill may accept yard waste. No energy exception in the section.
Vermont	Landfill rule reaches clippings	Act 148, Vermont DEC; timeline	July 1, 2016	Leaf and yard debris banned from trash. NERC 2020 lists grass. The state gave at least one town a variance (Troy and Jay).
West Virginia	Landfill rule reaches clippings	W. Va. Code 22-15A-22(c)	By 1994	Unlawful in a solid waste facility, except one built to compost or reuse it. Composting at home is listed as a legal route.
Wisconsin	Landfill rule reaches clippings	Wis. Stat. 287.07(2), DNR WA-073; Racine	Jan. 3, 1993	Grass clippings named; landfills and most incinerators. Energy-recovery incinerators are outside the ban.

1. Landfill rule reaches clippings14
2. Reaches clippings, gas or energy exception5
3. Only separated loads2
4. Grass left out3
5. Mandatory collection1

Source: The Green Industry Report compilation of state statutes and agency pages, Nov. 5, 2026 Counts come from the state table above. States outside the 25 were not coded.

Show the numbers

	States
Landfill rule reaches clippings	14
Reaches clippings, gas or energy exception	5
Only separated loads	2
Grass left out	3
Mandatory collection	1

Bags matter in 2 of those states. Illinois requires a biodegradable container for landfill-bound landscape waste, and Minnesota requires ASTM D6400 bags at metro transfer stations and compost sites unless you empty the bag and take it away. Outside the 25, Texas, Tennessee, Arizona and Virginia report no organics ban in the 2020 NERC compendium, while Kansas reports some county bans. That leaves the city code, which can be stricter in any state: IDEM says so outright for Indiana.

Street and drain rules are almost always local. Pioneer, Ohio, section 521.15 bars clippings on public streets and sidewalks and in storm drains and makes the owner answer for vendors, and Dyer, Tennessee, fines up to $50 plus court costs. On private woods you own, no rule we read bars piling your own clippings, but New Hampshire prohibits dumping in a wetland without a permit and 36 CFR 261.11(e) bars dumping debris brought from private property on National Forest land.