When RAF first helped me fill my first bins with cow manure last winter, I didn't really have a clue what I was doing. I had never composted on that scale before, and had never done any "hot" composting. I just saw the method on videos by Charles Dowding and Huw Richards and thought it looked like an easy way to make lots of compost...something I saw as a must-have if I wanted to switch to no-till gardening.
Besides having no experience in hot composting, I also didn't have a soil thermometer at the time I decided to set up the first bin.. But I ordered one on Amazon, and it arrived about a week after my second bin was filled. I was absolutely shocked when I took the temperature of the pile...it was almost 160° F!
Being the type of person I am (if I don't have something real to worry about, I make something up), that temperature reading stuck in my head and that night I tossed and turned all night long, worrying - or battling the "what-ifs" as my Mama calls it.
What if the bin catches on fire?
Is it heating up even more right now?Is it dry enough that the fire would get out and burn down the shop?
How would I put it out?
How hot is it right now?
Do I need to go check it right now?
I wonder how hot it is right now....
I think the frost would keep the fire from spreading.
Will the frost keep the fire from spreading?
Luckily, common sense won out and I didn't get up at 2 am to go check the temperature of the bin! When I did check it the next morning, it was still the same temperature. And after asking The Google about it several different ways, I felt a bit better, because it sounded like the pile would have to get up to around 200° F before it was at any risk of spontaneous combustion.
Really, 160° F is too hot for a compost pile. That means the bacterial action has gotten so intense that the bacteria are generating so much heat that they are creating conditions they can no longer tolerate, and are actually killing themselves. But while the quality of my compost might be degraded by that temperature, my small bin wasn't going to catch fire.
And as the articles I read predicted, the temperature pretty quickly dropped to around 140° F and it stayed right there for the next few days.
Time to turn the pile.
I learned a lot during that first turn. First, I learned that I hadn't set up my bins correctly. I had filled bin #1 with manure (the one at the far left as I faced the bins) and then I filled bin #2.
So when I got ready to turn the piles, I had to move the material from bin #1 into bin #3. That meant carrying every shovel full of manure six feet to the south, to the empty bin.
Rather than do that, I decided to put the manure into my cart - but that still meant loading it into the cart, pushing the cart over to the empty bin, then unloading it. Wow...I didn't realize I had put so much poo in there! It took probably a good hour and a half of work to move the pile!
At first, I was able to empty the cart by just tilting it up and dumping it, but as I moved more and more of the manure, I had to tie the front pallet up to keep everything from spilling out into the yard. That meant every shovel-full had to be lifted into the cart, and every shove-full had to be lifted out of the cart and over the pallet. It was quite a workout, to say the least.
Notice I said "shovel-full." That was mistake number two. While the frozen cow patties were easy to scoop up off the ground with a flat shovel, scooping the patties out of the bin with a shovel (technically a spade) was extremely difficult! The patties were turned every which way, so when I tried to put the shovel in, I would invariably hit a patty that was turned at a different angle, or hit a layer of leaves. It would have been so much easier to turn with a manure fork (which I subsequently bought!).
Patties...that was mistake number three. Because the cow patties were frozen when I scooped them up off the ground, I just dumped them into the bin as they were. I didn't make time to try to break them up into smaller pieces to expose more surface area for the bacteria to work on. That meant that active decomposition was really only happening on the outside of the patties. When I turned the pile that first time, I tried my best to break them up into smaller chunks.
And the leaves...that was mistake number four. Not only did the leaves form a surprisingly solid layer that was difficult to penetrate with a shovel, apparently it was also difficult for the bacteria to penetrate. At the first turn, I couldn't tell that the leaves had broken down any at all. They just looked like wet, matted leaves. Mental note to self: if you use leaves in the compost bin, try to shred them first!
Finally, mistake number five. I had piled some sticks and small tree branches at the bottom of the bin, thinking in my naïve mind that they'd break down. They will, but not that fast. So as I got near the bottom of the bin, I began to hit sticks that were intertwined and weighted down by the manure on top of them. I pulled some out, and tried to get as much manure off the top of them as I could, but I finally just gave up and left the last bit of manure in the bottom of the bin. The lesson? If you put stuff like that in your bin, cut, chop, or break it into small pieces!
As I dug down into the center of the pile, the leaves and manure looked like they had been covered with a thin coating of ashes. It again made me worry the the bin had been about to catch on fire! Asking The Google about it didn't turn up much, but there was one page on Houzz.com that had quite a bit of good discussion, along with some funny comments about the gray ashy substance.
But there was also a comment about a man who died after breathing fungal spores from compost.
I looked it up, and that did, in fact, happen.
The 47-year-old welder from Buckinghamshire, who has not been named, died in intensive care a week after being engulfed by "clouds of dust" when he opened bags of rotting plant material that had been left to fester, in a case reported in the Lancet.
Source: TheGuardian.com; accessed April 17, 2022
So there it was...more ammunition for "the what-ifs." That night, I couldn't stop thinking about the gray powdery stuff, and tried recreating the day's events in my head to see if I might have breathed in any of it. I finally exhausted myself with worry, and decided that first, I probably didn't breathe in anything because the wind was blowing pretty hard from my back as I was working; second, if I did breathe in anything, it was probably only a very minor amount; and third, if I did, it was too late to worry about it anyway.
I've turned the two bins three times now, and while I did try wearing one of my N95 masks at one point, I eventually gave up on that because it was a pretty warm, sunny day, and I decided I might be more likely to die of suffocation than from breathing in fungal spores.
After the third turn, the temperature in the bins never did go up above ambient, and there were quite a few beetles, earthworms, and other assorted critters down in the compost. Oh...and fire ants. I was quite annoyed to find that the fire ants had made themselves at home down near the bottom of the bin, but I don't know what I can do about that. I just went ahead and turned them over into the new bin. I sincerely hope lots of them got trapped in the now disorganized pile and died!
It was also interesting to me on the last turn how the material in the bins looked different and actually smelled like a forest floor...it had a nice "earthy" smell instead of a raw cow manure smell. I know there is still quite a bit of undecomposed material in the pile, but I think at this point, I'll just leave them be and see what happens.
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| Compost bin after a turn. Lots of undecomposed leaves on the top, but overall, it was starting to look pretty nice after only two turns. |
I couldn't resist trying some of the compost now though, even though it's probably still pretty "hot."
In Charles Dowding's "no dig" gardening approach, he puts down some type of barrier to block weeds, tops that barrier with compost, and then plants directly into the compost.
I didn't have enough "finished" compost to do that, but I did try an experiment with three of my broccoli plants. I put cardboard down on the ground, then piled some of my not-quite-finished cow manure compost in a mound on top of that. I then took three small cardboard shipping boxes, filled them with finished compost from my old "passive" compost bin, settled them down into the center of the composted cow manure pile, put a broccoli plant in each box, then covered the cow manure and compost-filled box with straw. So far I can't tell that it has hurt those three plants, and they might actually look better than the others that were just planted right into the ground.
And since celery is also supposed to like really rich soil, and since I've never grown celery before and really don't know what I'm doing, I decided to do another test. I had 12 celery plants...I put six of them in the ground in the garden, but the other six I planted in my middle compost bin.
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| Celery in the compost bin. I hope the compost isn't still too "hot" for the plants to survive there. |
Now...the "what-ifs" have already started in on me about the celery in the compost bin, but I'm going to ignore them. I'll just be sure to wash the celery really well in case there's any Escherichia coli contamination on them!