Clumpy compost, and roots in compost pile

VermontCathy Posts: 1,821 ✭✭✭✭✭
edited October 2020 in Composting & Soil Fertility

While I've had some success at making compost, the stuff I make in the rotary composter is never the nice, smooth, runs-through-your-fingers stuff that I buy locally.

When using the rotary composter, I get large clumps that are hard to pull apart when wet, and form hard lumps when dry. I can pull apart the wet clumps with some effort, or dry it out and then rub a couple of clumps together like sandpaper, letting the compost crumble to a powder.

My compost has a high content of freshly-mowed grass as the main source of green nitrogeneous material, coupled with kitchen scraps. I do not have a source of straw or hay. The green/brown ratio in the rotary composter is probably overweighted on green.

In my compost pile, separate from the rotary composter, I typically put a layer of brown leaves (if necessary, using last year's leaves, which I store in piles in the woods) as the brown material in between layers of grass. I haven't had as much trouble with the clumping in the pile, but it breaks down much, much slower than the rotary composter.

My guess is that the grass is not fully breaking down in the rotary composter, and the fibers in the grass are holding a clump together until forcibly pulled or sanded apart.

Has anyone else had this problem? What technique did you use to solve it? I don't want to stop using the rotary composter because it's so fast, and my husband likes it.

The compost pile has a different problem. Some kind of small but tough root quickly grows all through it, so by the time it is finished and I'm ready to put it on the garden, it's a real challenge to shovel it. I have to stand on the spade and push hard to break up these little roots in order to free a shovelful from the pile. It's harder work than shoveling the "bought" compost, and I am not able to get at all of the compost because of these roots.


  • blevinandwomba
    blevinandwomba Posts: 813 ✭✭✭✭

    Can't help you, but I can sympathize. I've had quack grass grow into a few different compost piles, making them almost unusable.

    I'm afraid I'm pretty ignorant about rotary composters, but why can't you put leaves in it?

  • Desiree
    Desiree Posts: 255 ✭✭✭

    When I used a rotary composter with leaves years ago, it turned to slimy leaves. I meant to try it again with mulched up leaf material but moved out before I could try it.

    I have a kitchen scrap/grass composter bin going for top dressings but for the majority of my yard waste I compost right where I am at. When I prune trees, I leave the branches at or near the base to dry and drop their leaves, I'll come back in the fall and cut/chop the branches for a winter mulch and the larger portions go to the kindling/log pile or the woodpile of unburnable wood.

  • I tried to use a rotary composter and it made awful compost. My sense is they don't get enough air and become aerobic and stay that way.

    As far as something growing through you compost pile could only be two things (1) roots from a neighboring plant or (2) roots from a plant you tossed into the pile. Did you mulch all your material before building the compost pile? Can you trace the roots with your hands to the source?

  • Annie Kate
    Annie Kate Posts: 680 ✭✭✭✭

    Quack grass in the compost pile would be a nightmare @blevinandwomba . I live in fear of that happening, especially now that we no longer have chickens to eat the quack grass I pull up and pulverize the roots. How did you solve that problem?

  • blevinandwomba
    blevinandwomba Posts: 813 ✭✭✭✭

    @Annie Kate I raked around it as best I could, then started a new compost pile somewhere else. Wish I had a better answer.

  • SherryA
    SherryA Posts: 314 ✭✭✭

    Could you use shredded paper in the rotary composter for more brown? Would that help?

  • Kelley
    Kelley Posts: 140 ✭✭✭

    are you checking the temp in your composter? Supposedly around 130 degrees Fahrenheit is supposed to kill weeds and seeds.

  • VermontCathy
    VermontCathy Posts: 1,821 ✭✭✭✭✭

    There's no need to check the temperature. I know it's not heating up enough! The only time I get significant heat in the main pile (not the rotary) is right after fresh-mowed grass is dumped on it.

    Unfortunately there seems to be a minimum volume of compost needed to get properly hot and thoroughly decayed, and I don't have enough material to reach it. (And most rotary composters aren't large enough to reach it even if full.)

    I compare the size of my little pile with the size of the ones where I buy extra compost, and there's no comparison. Compost-making seems to be one garden process that really benefits from scale.

  • greyfurball
    greyfurball Posts: 591 ✭✭✭✭

    @VermontCathy most of your questions, you have already figured out the answers. And your answers are right, it's just that you aren't following through and doing it.

    So #1 yes your greens/browns ratio is way off. You always need 3-5 times more browns than greens. That is the main reason why you rotary is all clumpy. You dont have enough browns in there to reduce the moisture from all the greens.

    #2 As for the root problem, I gather this is the pile you have on the ground and yes, that root system is in your original soil area and it just grows up since your pile is just sitting there. I get the impression you do not turn your compost pile every week or two. This alone would solve a lot of that root problem because you would consistently be breaking apart those roots in there. But myself, a better suggestion (since I would not want those roots in my finished compost because it could get into my garden soil also when I fill or top off the beds). Move the ground compost pile to somewhere else. I'm not sure if you are from Vermont but if so, that is ideal We are just going into the winter season. Lay out a bunch of cardboard, flattened in an area about 2 feet wider and longer than you want your compost pile to be. Stack several layers. you are trying to eliminate all heat, light and moisture sources getting to that area. Then cover that cardboard with black plstic for the entire Fall/Winter/Spring. Don't remove it until next year when you are going to start your new compost pile for the 2021 season. Start fresh with an area not disturbed with those roots and you won't have the problem anymore.

    #3 As for the comment about yours is not as fine and smooth as store-bought compost... the part they don't tell you is every manufacturer sifts their compost (after it is run through a grinder) to get that smooth fine texture. Some home gardeners do also, some don't. That smooth fine texture is not necessary for your garden beds. If there is small clumps and a few lumps when you spread it, the materials not completely broken down yet will continue to break down in your soil. Just spread it out on top of your soil and rake it in. You can still seed or plant with those small clumps in your garden bed.

  • VermontCathy
    VermontCathy Posts: 1,821 ✭✭✭✭✭

    Great advice, thank you!

    I had not quite fully realized that clumpy compost = low C/N ratio.

    You are right that I only turn the compost pile about twice a year.

    I'll think about it and see if I can find a better place for the pile. The challenge is that my husband doesn't want it on the lawn, which means it gets placed on the edge of the woods, where lots of plants can send up roots...

    I have a large, multi-year pile of leaves in the woods that I let decompose into leaf mold. It has the same problem with roots, for the same reason.

    Anyone else have the spousal-permission gardening problem? :-)

  • greyfurball
    greyfurball Posts: 591 ✭✭✭✭

    @VermontCathy just in case you do not realize this, try to get your additives you place in your compost pile as small as you can get them. This allows them to decompose much faster so you do not have to wait so long until your pile is ready to use.

    Thus, the old leaves (great for a brown for your pile), if you have a mulching mower or lawn tractor, these are great, just mow over them until they are broken up into pieces. Then put them in your pile. You have just reduced your wait time by half or more. Also, add vegetable and fruit waste from your kitchen or just from the garden. Then regular black and white newspaper can be used. Google search around you and see if you can find any hay/straw/alfalfa grass/used coffee grounds/ peanut shells/ etc. Just make sure it is all organic. The more things you can come up with to add to your pile, the faster it decomposes and the more nutrition you are adding to the final decomposed soil.

    Then if you get out there and turn that pile, or at least stick a pitchfork into it and fluff it every week or two, you will have usable compost even faster.

    Actually, once you get on a consistent schedule you will learn to love the pile more than the rotary. I got rid of my rotary and now have a 3 bin and a large chicken wire pile and these two together make plenty of compost every garden season for me just because I made myself set up a schedule to work those piles and make myself do it.

    I have a relatively large garden now (it grows every year) and my piles make enough compost for all of it. My garden is up to just short 3000 sq yds now and I work all areas all season. As one crop matures and comes out, something else goes in. Often I also inter-plant, say fast radishes are sown among slow snow peas or spinach etc. all Spring/Summer and Fall so I never have bare soil showing. But every time I remove one crop I add more fresh compost to boost the soil's nutrition. Then in the early Spring and late Fall every bed is again refreshed with new compost.

    So if you are willing to put in the effort you never have to buy compost again.

  • VermontCathy
    VermontCathy Posts: 1,821 ✭✭✭✭✭

    I tried running the lawn mower over the leaves, but my mower didn't chop them up very well. It may work better for other mowers.

    I turned the pile and added layers of leaves in between the existing layers. I'll turn it over again in the spring, probably several times. (We are quickly approaching the season when everything will freeze solid and cannot be turned.)