So I have been composting for about three years now using a traditional, barrel-style composter. Just the basic kind that standsup--you throw stuff in the top and pull it out the bottom. This always worked okay for me, but the squirrels had finally cut enough holes into the side that I decided to upgrade this spring.
I bought a Lifetime Dual Barrel spinning composter at Costco for $100. Great deal I figured.
Here's the problem though--my compost stinks to high heaven and it seems like a major colony of black soldier fly larvae have taken up residence in my pile. I think that's what it is at least... looks like yellow/white maggot-y things about a inch to inch and a half long.
The bad smell made me think that I just had too much rotting stuff in there, so I threw in a ton of old moldy hay (as a brown item) and spun it around and around. About a week later it was no better so I figured that I may be able to get rid of the bugs by heating it up. In went a bag of fresh grass clippings, which in the past have always given me great cooking power, even if they tend to clump a bit.
So I have done both of those things but I still have a really stinky mess on my hands. I've always been very passive about my compost, but it seems like since I transitioned to a spinning one I spend more and more time managing it.
I know that someone out there has the answer for me. What am I doing wrong?
Hey Tom, you're not far from us, we're in southern RI.
Can you describe the stinky smell? Is it like anaerobic bacteria? Is it too wet? Do you put meat or animal products in it? Being up off the ground separates the compost roller from a lot of good decomposition action.
If I were you I'd plop the compost out of the roller into/onto something on the ground like a cardboard box, cover it with some mulch, leave it for a while and start over with the roller. I've got plenty of space and compost materials though
Your "compost" has gone anaerobic ... which means it isn't compost any more. If it smells then your likely doing it wrong.
Most of my knowledge about compost processes have informed me to never compost a pile less than 1m^3 as the temperature doesn't get high enough.
Might I suggest freezing your "greens" till you have enough of them to make a bigger pile and ditching the rotating bin? Either that or add more carbon. When you go anaerobic the only way to bring it back is to add more carbon or start over. Get a good brown / green ratio mix going then slowly add in your now high nitrogen source (the older failed compost).
Be very careful about adding extra water at this point as it will only make things worse.
I am sure there are others who have experience here with the turning bins who might have better suggestions but I figured I would throw in what I could for now.
Thanks for your advice all. I agree that the pile has turned anaerobic on me. My real focus is on how do I get it back.
I was thinking of just keeping adding in browns. The pile is very wet, although I never really add water to it. I do add way more greens than browns as a general rule, but that has never really hurt things before. I just throw in a lot of kitchen scraps to my pile. I don't have a ton of browns, but I can keep dumping straw into things. That may help to loosen it up a bit and help get more air into the center.
Should I be concerned about the larvae that has clearly taken up residence in my pile? I think that it is probably black soldier fly larvae, but I am really not sure. I'm not much of a woodsman! Since the pile is up in a rotating bin, they aren't going to leave the pile. So do I just wait for their natural life cycle to pass and let them fly away? Does anybody think that they are offering any tilling or other beneficial work for me at this point?
1-Too many greens
With all other conditions right, the C:N balance of the heap is tilted to N. You'll get a rank odor and the bugs will love it. Being late summer, the bugs have gone through several reproductive cycles and will usually have their highest population of the year. Give em optimal conditions, they'll take over.
Solution: add lots of browns, toss the heap. Mixing in the browns will bring balance back into the heap and absorb odors. The bugs will run their course and contribute greatly to decomposing the heap.
2-Too many greens, soggy mess
Lots of grass clippings and food scraps bring lots of moisture along and need to be balanced with browns to absorb the moisture. It is that moisture that promotes microbial activity, but it also prevents oxygen flow which limits the microbial activity to anaerobic in nature. Your heap is fermenting rather than composting. Since you have lots of bugs, there is plenty of oxygen.
Solution: add dry browns in no small amount, toss the pile. The browns will absorb the excess moisture and add oxygen-containing air pockets. Tossing the pile brings in oxygen.
3-Too much protein
Meat, cheese, dairy, dead worms and bugs bring lots of protein to the heap. Protein decay involves a process known as putrefaction. It's smelly and can attract vermin. This is the chief reason compost instructions tell you not to add these items even though they'll rot just fine.
Solution: add browns, toss the pile. In this instance the browns serve to absorb the volatile aromatic compounds as well as fluids and excess moisture which enables the process.
4-Too much moisture
Perhaps your mix of greens and browns is right but the moisture is too high. The heap is packed and the water prevents airflow. Same situation as #2, but more of a musty, earthy odor which is not offensive.
Solution: add greens and browns in the right proportions, toss the pile. This adds material to absorb the excess water. You can also spread out the pile to let it dry out.
5-Not enough air flow
All conditions are right but the pile is not breathing. All the oxygen is used up.
Solution: Toss the heap. Adding ventilation to enclosed bins would alleviate further troubles.
As for the bugs...
It's the odor that has attracted the egg laying adults. Every bug in range will find the heap and add eggs. If you feed greens to the heap, the bugs will keep on populating to the point of overshoot. Once the food source is depleted they will die off en mass. From what you describe you have problem #1 and will move into problem #3. Hay, dry grass, leaves, shredded newspaper, sawdust, wood chips, bark, should be added in good volume. If getting rid of the bugs is the objective, dump the heap onto the ground, spread it out, let the birds get to it. They'll feast on the bugs in preparation for migration.
Seed the Mind, Harvest Ideas.
That is the one that I have. There is a horizontal bar that runs through the center which helps add air to it. Things seem pretty loose in it--just really wet. There seem to be enough cracks between the panels to let the water drain out. Some has that you can see under it. There is no way for the larvae to get out though.
I run a pair of tumblers and they are the best composters I have ever had. If its a bit stinky just add some dry leaves, hay or shredded paper and it will settle down in a week or two. Just make sure you keep tumbling it a couple of times a day. As for the BSF larvae, they are great fish or chook food and a real resource. If you have the twin setup start using the second tumbler till the stinky one settles down.
Just to update the thread, I dumped in a ton of moldy hay to the barrel and have been turning it almost daily.
I don't see too much larvae anymore. I found what looked like a nest of them and dug them out and relocated them elsewhere. I do see a few when I turn it, but not to the extent as before.
The stinky-ness has gone, but things aren't hot anymore. Should I just keep turning and turning it or is there something that I should add to get it going again? Winter is coming soon and it usually turns into an ice brick for a few months a year. Wasn't sure whether I should do something this fall.
The hay has swung the CN ratio to favor carbon. The mess should cool, smell better and be dryer than before. If the pile is well blended, additional turning would only be needed every few days (at most) to bring in oxygen.
Moving the balance back to the N side can be done gradually to warm up the compost, this time without so much moisture. Give the bin a spin to mixc it up.
Come winter, the microbes will freeze right along with the compost. They'll pick up where they left off once they thaw out.
Seed the Mind, Harvest Ideas.
Something that popped into my head on identifying those BSF larva: Black soldier flies, unlike most other flies, don't lay eggs directly in their food. They would likely lay their eggs on the walls of your composter.
Although, I suppose if you've been turning the drum, then that advice won't help very much
"There is nothing, Sir, too little for so little a creature as man. It is by studying little things that we attain the great art of having as little misery and as much happiness as possible." - Samuel Johnson
permaculture is largely about replacing oil with people. And one tiny ad:
paul's patreon stuff got his videos and podcasts running again!