Composting grass clippings

In my large suburban yard I have a mix of standard lawn and "wild" areas.  I have always had trouble composting the grass clippings (greens) in the late spring/summer because I usually don't have any browns to mix with the tons of grass clippings from mowing the lawn (yes I know I should reduce the size of my lawn).  What usually happens is the lawn clippings form dense mats which are a real pain to mix with the leaves & sticks in the fall.  My neighbor recently asked if he could put his lawn clippings in my compost.  Although it pained me I had to tell him no, because I have been unable to compost lawn clippings quickly (their lawn is even bigger than mine).  By taking his clippings I would end up with a huge stinking mountain of matted clippings.

When the "wild" area gets really tall with grass & etc. I have found it best to cut it with a scythe vs. a string trimmer or the mower.  The string trimmer gets clogged up with the long stems, and the mower gets clogged up just due to the volume of the tall grass (especially if the grass is moist).  With both devices I have to stop at least once every few minutes to unclog things.  The scythe presents no such problems, plus it gives me rows of "hay" to use for mulch or compost, and it has other advantages.

I always put the lawn clippings in the compost bin, and usually just leave the "scythe hay" on the ground.  However I was recently using the scythe hay for mulch and had collected a bunch of it into a pile (haystack, I guess).  As I mentioned, the lawn clippings turn into a stinking layer of goo on the bottom, with a dry powdery layer in the middle and dry & brown on top.  However the haystack did not do this - it was just evenly dry throughout.  I had the idea to mix the two in my compost bin, and with the addition of some water and a bit of turning, it seems to be cooking really well.  I don't normally turn my pile much nor add water to it, but I used up all my compost this spring and I need to replenish my supply ASAP.

I have included two compostable plastic items that I got recently - a chip bag and a cup.  The chip bag seems to be breaking down nicely, but nothing is happening with the cup yet.

So it seems that you can get your lawn clippings cooking by mixing them with some tall hay/straw and water.  If you have a way of cutting tall grass (e.g. scythe), you might want to let a corner of your lawn grow tall so you can cut it for hay/straw to mix with the lawn clippings.  Or you could probably just buy a bale of straw to mix in.

I'm guessing that this works because 1) the tall grass is more "woody" (brown) than regular lawn clippings, and 2) the stacked tall grass contains a lot of air pockets and thus keeps the pile more aerobic.

In my experience, the biggest factor is aeration. Anything that will create air spaces will help - twigs, corn stalks, vine clippings, vegetable waste, balls of crumpled paper, chunks of sod. I always add twigs and branches to my compost. When the rest of the material is well rotted, the twigs and branches are still there. I take them out and add them to the green stuff just going into the pile.

I dried half of grass clippings and add it to the pile later on.

if your gardens are large enough you probably would be far better off putting the clippings directly on the gardens as a thinner mulch than trying to compost them..don't pile them deeply on the garden just kinda sprinkle them around the plants and as they dry out add more..maybe smaller piles ..thinner piles..until they dry out more like hay..and then directly on the garden.

Brenda Groth wrote:
if your gardens are large enough you probably would be far better off putting the clippings directly on the gardens as a thinner mulch than trying to compost them..don't pile them deeply on the garden just kinda sprinkle them around the plants and as they dry out add more..maybe smaller piles ..thinner piles..until they dry out more like hay..and then directly on the garden.

Yes, that would be good, but at the moment I have no garden at all!  Thus an overabundance of lawn clippings.  Also I used up all my compost so I am trying to make more ASAP.

Most people in my neighborhood use a landscaping service (who haul away the clippings) and also use curbside yard debris pickup.  So all their organic matter is carted away.  Then of course they get compost & mulch delivered.  Silly I know but that's the way it is right now.  I only know of one other person on my street (out of 18 houses) who has a compost pile.

If you don't have a garden, what did you use the compost on?

oh then here is a perfect answer...if you are planning a garden and haven't gotten one yet you are in the perfect place for building beds with sheet mulch.

you lay down your cardboard and any other brown stuff that is avail to kill the grass and cover it with some grass clippings..(green and brown) over the areas where you want your beds..cardboard can be come by rather easily from any store..they give it away..so lay it down overlapping it 3 + " and smother it with grass clippings..by spring your garden will be ready to plant

Fresh green glass clippings are a Green, about 12-1 C:N.  Dried grass clippings, aka hay, has considerably less N, coming in at around 40:1.  Mixed together, the blend will compost just fine.  If you have an abundance of green clippings, they will also compost just fine, but will heat up rapidly and begin to put out an odor.  God forbid we offend our neighbors with an uncomfortable odor! 

Lots of options for too much greens
-spread them to dry in the sun, blend with fresh in a few days
-spread out the heap, allowing the moisture to dissapate
-Turn the heap more frequently when it has an abundance of greens.
-add more browns: leaves, sticks, brush, newspaper, hay, wood chips, sawdust, scrap lumber, whatever you can get your hands on.

In my experience, greens are harder to come by than browns.  It is a handy thing to have 2 heaps going.  1 is the hot pile into which all my greens are added, the other is a pile of just browns, mostly leaves.  The slow brown pile produces no odor and for the most part stays content just sitting there for a long time doing nothing.  Reminds me of a couple of guys I work with.  If you had such a heap, perhaps hidden in one of the wild areas, you would be able to draw from it when you have a sudden influx of greens, such as your neighbor mowing his lawn. 

I've found that grass clippings are just about the fastest things to compost, being unidentifiable in a week if turned every couple of days.  For me, N is expensive.  By that I mean I'm on the prowl for it continuously, can't get enough of that darn good stuff.

One last option I'll toss out there:
If you can't compost the stuff, perhaps you can turn it into the soil.  A tiller or a good shovel can make good use of the stuff.  Once the stuff is buried in the ground a few inches, it will decay just fine, releasing all those yummy nutrients directly into the soil. 

Take your neighbor's clippings for your pile.  Leave your own on your lawn.  If you have a surplus for the pile, take some of the suggestions given so far, they all sound great!  Also, when I bought my first house, I used to take the clippings I'd collect from my rental house mowings and just chuck them around the new house's lawn (feed my own soil if I was going to go through the work of mowing a lawn!).  That could be another option with surplus neighbor clippings.  You can never improve any of your soil enough, whether it is to be garden or lawn!

Don't worry about mulching blades if you don't have 'em (since it seems all you do is collect).  Clippings will compost just fine in place, no matter how tiny or long they're cut.

my only concern about any neighbors is to ask if they use herbicides or pesticides on their lawn before taking their clippings.

CBostic wrote:
If you don't have a garden, what did you use the compost on?

I should have said I am "between gardens".    We are redesigning our backyard using mostly native plants, so I have a small nursery growing plants (in pots) that I will use in the coming months.  I use a mix of compost and soil when planting pots.  Also when I put a plant in its final location, I mix some compost in.  And of course we will have a small keyhole garden.

Yes I will definitely ask my neighbor about the chemicals he uses.  I would guess he uses the standard "weed & feed" - would that make the clippings useless for compost?

I have never been able to compost grass clippings alone very successfully.  If the clippings are moist (Oct-June), they form mats and stink badly, and are a huge pain to turn because of the mats.  If they are fairly dry (June-Sept), they turn into this sort of stinking powder and turning them is kind of like trying to turn a pile of cotton candy.  I could add water but it seems impossible to add enough without causing the matting problem.

I do leave the clippings on the lawn whenever I can, but my wife is vehemently opposed to that because she thinks it looks trashy, and pets & kids sometimes track clippings into the house (and she grew up in a neighborhood of manicured yards where chemicals ruled).  So if she mows, she always bags.  Suffice to say that we don't see eye to eye on many aspects of yard maintenance.   

I seem to have either an overabundance of greens (spring & summer), or an overabundance of browns (fall), but rarely a nice mix of both.  I have started to store some browns (branches & leaves) but the leaves usually decompose on their own before I can use them, and the branches usually take a very long time to break down to the point where I can mix them in the pile without creating a giant blob of interlocking branches which is nearly impossible to turn.   I should probably just chop them up with the mower or something.

I have started getting some tree trimmings from a local tree service, but I need those mostly for paths right now. 

I do occasionally have a completely full compost bin, when that occurs I just spread the clippings in a wild area of the yard, as someone suggested.  But normally my demand for compost is greater than my supply so I want to use the lawn clippings for compost if I can.

I turned the pile last night, it is cooking really well, I think it should be pretty much done in another week.  The compostable chip bag is completely gone.  Still not much happening with the compostable cup.

I'll see if I can post some photos of my bin/pile. 

Oh! That makes sense ... that would use a lot of compost.

if one uses weed and feed, yes, it will kill your plants..so don't put it on them or in your compost pile..

i believe the package tells you to NOT mow toward your flower beds..so that tells you right there that the clippings if they get on your beds are going to kill them..

it is a herbicide and it doesn't quickly go inert as it is a LONG LASTING herbicide..in most cases...so yeah...don't accept them

Another way to help reduce odor is to add agricultural lime and/or soil to the pile. A pile of sticks and green grass clippings, with the occasional layer of dirt, can be left for a year or so.

If you suspect there is long-lived weed killer in your compost, you can plant three peas in a pot of soil with that compost mixed in, and three in a pot with some compost you know to be clean. Peas are particularly sensitive. If it isn't usable on dicot plants, it could still be used on a bed of garlic, or pasteurized and used to grow mushrooms. Either of these uses will give the soil food web more time and energy to work on breaking them down.

I promised to post a couple of photos of my compost bin and the pile of mixed scythed grass hay and lawnmower clippings.  I started this pile just over two weeks ago and have been turning it and adding water every day or two. 

I heard long ago that a good mix will compost in 2 weeks if you turn it every day and keep the moisture level right.  I have never actually tried that until now.  I did not turn it every day, but at least every 2 days.  And I added a LOT of water, since it got really hot (the pile as well as the weather).  Many parts of the pile are done (it's been 15 days) but it will probably be another week until the whole thing is done.

About mid-way through, it created a massive cloud of steam when I turned it.  Even in the middle of July.

The original pile filled the entire bin and was a foot above the stones.  You can see how much it has shrunk.

Beautiful! 

Brings a tear to my eye...  Makes me want to go turn mine, just to hurry it along (I seldom tend to my pile, just keep stacking on).  Maybe next chance I get...which may be a few weeks away! 

Jeremy Bunag wrote:
Beautiful!   

Brings a tear to my eye...  Makes me want to go turn mine, just to hurry it along (I seldom tend to my pile, just keep stacking on).  Maybe next chance I get...which may be a few weeks away! 

Thanks!  I know what you mean "brings a tear to my eye" - though most people cannot relate to the emotional side of compost. 

I am in a hurry with this one because I need compost for a seedball project which is starting on Wednesday.