opabinia51
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Hot Compost

Making a hot compost pile is really quite simple, I was a little scared to try it but, now that I have, I realize how easy it is.

All you do is save up equal amounts of greens and browns and mix them together in a pile that is at least 3x3x3 and turn every few days. In as little as three weeks you will have compost.

Also, it is especially important to chop up all of your material as much as possible.


One great source for greens right now is corn husks and carrot tops. I just go down to one of my local farm markets where they sell carrots, corn and the like and they let me take all the husks that I want and while I am collecting those, the one guy comes over and gives me all the carrot tops.

Be sure to turn at least every other day. I had decided to wait three days to turn the pile and on the second day turned it instead to find ashes in the center of my pile! Wow! Anyway, if your pile is a little to hot (like mine was) add some browns (mulched up leaves for me).

I also chop up all the corn cobs and put them into the compost. And the shells from shelling peas are also a brown.

Incidentally, Carrot tops are loaded with nutrients for both the soil and for us. Try putting them in a salad or a stirfry and you will be pleasantly surprised

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Grey
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Smokin! Great info - as soon as I can, I want to do some of this hot compost because I need some ASAP in my neglected-for-years little yard.

opabinia51
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Hi Grey, it really is smoking, I mean really is :shock: Be sure to turn the compost at least every other day. And have a 50/50 mixture of greens and browns, I had to many greens in mine at first and when I turned it, there were ashes!!! Yikesu desu yo! (That's pseudo japanese for YIKES!)

Hot composting is really good for killing seeds, diseases and pathogens as well.

grandpasrose
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Just don't singe those mullets you guys! :wink:
VAL
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Composting

I was most intrigued to read that as a soil scientist you were unfamiliar with hot composing. Being a backyard composter I point out several areas of concern with the posted compost recipe.

The usual ratio of carbon to nitrogen is 30:1 . Backyard composters can probably get away with 15:1. The lower the carbon ratio drops the more often the compost has to be turned.

Internal temperature of the compost pile needs monitering. Anything above 130 degrees, for me, is iffy. Mine never gets above 125 degrees. Anything higher can kill the soil critters and remove nutrients from the plant matter rendering compost sterile and of little value in supporting plant growth. If you produced ash I wonder just how high the temp went. Out of curiousity, can you do a soil test on this compost now to check for presence of soil critters and nutrients? Hot composting requires a temperature probe.

Turning the pile controls temperature and provides oxygen. Keeping several low piles rather than one big one is easier for turning. What one wants to accomplish by turning is to remove the center of the pile, push the sides into the middle and put what was in the middle on the top. The middle of a small pile can be forked into a wheelbarrow and then emptied overtop.

Another concern is lack of mention of moisture. Compost piles need dampness throughout or all the componets can't work together to make compost. This could be another reason for ash appearing in your compost pile.

You also might consider having a top that does not come into direct contact with the compost surface, but still keeps rain from leaching out nutrients. This acts as a vent for heat build-up.

I use hot compost sparingly, adding an inch to every garden in the spring and as a mulch for weakened or new plants. The remainder of the compost I use comes from cold composting piles which do no require exact monitering. I try for 1, 2 and 3 year old piles, using from the 3 year pile first.

You are fortunate that your compost pile did not start smoking or catch fire. Our fire department makes more than a few runs a year on compost fires. Some take several hours to extinguish, another reason I avoid large high piles. Most times a neighbor smells smoke, thinks another neighbors garage is on fire and calls the fire department. What a bummer to get a $500 fire run bill for ones compost pile. And then find out homeowners insurance will cover only $200 .

opabinia51
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Hi. I'm not actually a soil Scientist. My area of study is Marine biology. Your points are all very valid. Thanks for your input.

Yes, there I have been thinking about the ash problem that I had, and lack of moisture could have well been the problem. The pile now has a lot of moisture in it but, I was going to use the hose while turning it today anyway. I just added four more garbabe bags of mulched corn husks/carrot tops as well as maple leaves last night. Not to mention a five gallon bucket of kitchen wastes (chopped corn cobs, ground peanut shells, cut up pea pods, carrot peelings, potatoe peelings, apple cores and so on.)

I don' think that the compost will be completely sterile after having the ash. Ash does not lack nutrients, it just has less of them. If you refer to the thread that I have on NPK values, a lot of the analyses were done after burning the materials (hence, the word "ash" next to them).

However, burning the material does decrease the amount of humus that will be in the pile. So yes, ideally one would want as little ash in the pile as possible and a good wetting with the hose is a good way to prevent this. As well as a healthy dose of browns in the pile.

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I'm taking loads out of my regular (this year pile, versus next year pile) batch and dumping them in my tumbler for just this effect; I've gotten three batches already with another due this week. Good stuff, I've been topdressing the veggie garden with it (roses too)

Scott

opabinia51
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Compost is great stuff, isn't it? Yesterday I added three or four buckets of seaweed and I gunged out my garden; picking out all that infernal morning glory, any grasses, leftover clover and so on. Anyway, most of it is in the compost pile now.

Before adding all that good stuff, turnedd the pile, soaking it down with a hose as I turned it. The hot compost looks really, really nice!

The other day (Saturday) I also added grass clippings to both my hot compost pile and my leaf mulch pile.

grandpasrose
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You are so lucky Opa, that you live so close to a natural supply of seaweed! It is wonderful stuff, but hard to come by up here - unless of course, you beg a friend or relative!! :lol:
Enjoy! :wink:
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opabinia51
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Yes, I love going down to the beach to collect seaweed. Everyone always asks me what I do with it and I tell them that it goes into my garden and that it is like black gold.

I turned the compost pile and added some maple leaves to it today as well as some carrot tops. It's doing great. Almost like having a pet!

grandpasrose
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But what a rewarding pet it is!! My compost has been getting it's share of apple leavings (cores, peels, etc) the last few days! I think I am going to start dreaming about apples! I can't believe how early they are this year - I think because of all the rain we had earlier this year with the hot spring, and now hot dry weather for more than a month. Very strange year for the garden - sure can't count on my garden log as a guide for timing this year!!!! :lol:
VAL
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opabinia51
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Yes, it sure is. How many pets can you think of provide the owner with such lovely rewards? None, off the top of my head.

grandpasrose
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Unless you include all the incredible loving my adorable cat gives me!! :lol:
VAL
VAL (Grandpa's Rose)

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Anything like the presents our cats bring and it get's a little grizzly at times..

But you all are right; I have taken more and more pleasure in turning and tumbling.. :lol:

Scott

opabinia51
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Just finished brushing my cat half an hour ago. The brushed out fur (sp?) goes straight into the compost bucket.
Apparently, hair and fir (which is it?) is high in Nitrogen. But, the basic structure of an amino acid (minus the remainder group) has a 2:1 ratio of Carbon to Nitrogen so, I would personally think that hair would be a brown. I guess those remainder groups have a C:N ratio that is closer to one.

I don't know.

Anyway, the cat feeds my other pets (the compost piles) as well. :wink:

grandpasrose
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Opa, it's "fur"! - "fir" is a tree.
I never thought of putting the fur from brushing my cat in the compost - thanks for the idea! :wink:
VAL
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opabinia51
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Thanks, I new that "fir" was a tree but, for some reason I became confus-ed about fir and fur. "Fur" just looked (and still looks) wrong to me.

Yes, the cat fur (still looks wrong to me) and for that matter human hair thing is really good. First of all, less things to throw away and second of all; more good stuff for the soil.

Though, I will admit that I am still leary about putting human hair into my compost pile. I don't know just a mindset, I guess.

grandpasrose
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Isn't that wierd when a word you've always used suddenly doesn't look right?
Anyway, I knew about human hair, and have put in compost, but for some reason never went further down the line to the cat fur! Keep the mind open!!!! 8)
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We need to draw the line somewhere before kitchen sinks guys... :lol:

I jest; it's been a great thread to get folks thinking about how household waste is utilized and more importantly, how it's not being utilized yet. Keep up the good work! 8)

Scott

grandpasrose
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How about the kitchen sink? :lol: I'm sure it has something to add to the mix! :wink:
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opabinia51
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Hmmmm, Kitchen Sinks. Lots of iron, some aluminum silicates. Could be good. Of course, it would be a really slow decomposition. :wink:

(Talk about a thread getting off topic :roll: )

Yes, it always amazes me the number of things that can be composted, and not to mention the number of things that people throw away. I've been house sitting for my mother for the past three weeks and I produce about half a can of gabage (if that) per week where, they fill the can each week.

Composting is amazing, and all this stuff that we throw away, can really help our gardens and us. I have another list (that is really inclusive) of NPK values that is a lot longer.

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I have been finishing my stuff in a tumbler; I'd say that's hot composting by definition. Or am I missing something here...?

opabinia51
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Well, by definition a "hot" compost pile is a compost pile with about a 50/50 ratio of greens to browns that is turned every few days. And hot compost piles give off a lot of heat. Hence the name. At one point, mine was so hot that I could hardly stand being next to it.

In fact, my Aunt and Cousin were sunning themselves on the lawn and when I started turning the compost pile, they had to move because of all the heat that was given off. And there is no bad smell.

Of course, think about poor me, they were lucky because they were wearing bikinis but, I had jeans and a shirt hot. Wow, really hot to wear when turning the compost pile.

opabinia51
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Yes, once your hot compost pile cools down (as mine now has) you can still continue adding things to it. In fact, my once "hot compost' is now teaming with worms. I add leaves and plant matter to it each week. It's going to be great for spreading over my garden next spring!

Be sure to cover any compost piles up within the next month, Fall and Winter rains can leach out vital nutrients. Though, if you hot compost is still HOT, don't put any plastic over it. The plastic may melt or even worse, catch on fire.

Also, I would recommend never ever hot composting next to your house. Many a fire has started with people forgetting about their hot composts.

Charlie MV
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Great post. I ground up entire corn plants, cobs husks stalks in our chipper yesterday. The pile is 4x4x3. The pile is hot...really hot. I see here that I should turn it about every 3 days and keep it damp and uncovered while it's this hot. We have to leave town for a couple of days next week. If I soak it down the day I leave will there be much fire danger?

opabinia51
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Ideally a hot compost should be turned everyday, yes and just keep it damp, not soaking wet.

good luck with your compost!
Feed the soil, not the plants.

Charlie MV
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All I can say is wow. It does get hot, it does make a little ash, it is like a pet and I never believed I'd have cooked compost in 3 weeks. I believe now.

opabinia51
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Yes, I have gotten ash as well with my corn husks et al. With hot composting you can have soil in a month. It's really quite amazing.
Feed the soil, not the plants.

alisios
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I was amazed when I saw my compost pile steaming in the winter.

chagen
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Hot Pile Question

Everything I've read about hot pile composting say to shred things as small as possible. I will be composting biodegradable diapers (made mainly from corn & sawdust). Do I need to shred them first, and are the considered greens or browns?
Thanks!!!

chagen
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Everything I've read about hot pile composting say to shred things as small as possible. I will be composting biodegradable diapers (made mainly from corn & sawdust). Do I need to shred them first, and are the considered greens or browns?
Thanks!!!

rot
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Decomposition is a function of surface area. The greater the surface area exposed to the process the faster decomposition occurs. Shredding will increase the surface area. The larger the pieces the longer they will take to breakdown.

If the stuff is too small, not enough air gets in between pieces and things will smother. Try adding too much coffee grounds sometime and you will end up with the gooey mess I made once.

I hope you get things really hot throwing in diapers. Could be a pathogen issue if don't get things hot enough. The other path would be a 1 to 2 year cycle letting the worms do all the work.
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2cents
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diapers

chagen wrote:Everything I've read about hot pile composting say to shred things as small as possible. I will be composting biodegradable diapers (made mainly from corn & sawdust). Do I need to shred them first, and are the considered greens or browns?
Thanks!!!
Green vs Brown
The urea is the liquid it would be a green or nitrogen source if there is feces I am not sure.
The bio-degradable diaper(corn & sawdust) would be a brown or carbon source.

So I guess it is both a green and brown

These will likely compost in 2-3 months in a hot compost or 6-12 months in an anaerobic or vermicompost compost.
IMHO

chagen
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Is it possible to do a hot pile compost in a smaller dimension (say 2x2x3 feet) if you use a hot compost starter?
Thanks!!

Charlie MV
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My winter rye gives me enough green to heat a pile. Asmall pile will get hot...just not as hot as a larger one.

rot
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Close enough for government work

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2 x 2 x 3 is 18 cu ft. My little hot compost bins are 17 cu ft and work fine.

120 F - 130 F seems pretty standard if you fill your bin up all at once with a decent mix. You can get higher temperatures with more work and optimal mixes, minding the moisture, etc. I use what's on hand and don't worry too much about getting the perfect mix of ingredients. My operation these days is geared towards digesting organics as opposed to trying to produce as much compost as possible.

Smaller bins are easier to turn too.
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jpcvb
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Lazy and easy composting and it works great !

I used to turn my compost once a week but got tired to do so therefore I continued to throw my kitchen scrap in it with a layer of dry leaves gathered in bags in fall for the whole year and to pour some rain water kept aside in a container next to it (gathered also almost once a year since rain is so rare in Southern Cal.) and realized that beautiful worms took over and are doing my job : nothing now to do but waiting for the worms to disapear at the level of the front door at the bottom of my composter which is a sign that this part of the compost is ready to be harvested, wereas I continue to add the kitchen garbage on the top of it in an endless virtuous circle ... I pull all I can and leave it to cure in containers and use it according to need (either diluted in water or as such (humus form) added to soil (in pots or directly in garden).
I didn't by the worms (being from the country side the idea of buying worms was outrageous to me) they just came by themselves ... I don't separate worms from compost either when some remain since they are good for the soil and because they reproduce as fast as their population diminishes, no need to bother ...
Last point I put my composter directly on the ground but on a strong wire netting to prevent rodents to dig tunnels to reach the compost and my delicious worms : yes they tried once ... not anymore ...
Hope it might useful to someone ...

TZ -OH6
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Are you certain that "ash" wasn't just fungal hyphae and spores? I have 6 ft piles of woodchip compost that get turned only after they cool down (once every 4-6 weeks). The turning starts them cooking again. The interiors of these piles resembles ash and the spores puff up like smoke, and yes, the organic material is a very dark brown because of the humification of the lignin (it is not char), but temps do not get anywhere near what is needed for flame-ash.

rot
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oops - bad math

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Oops. 2 x 2 x 3 is 12 cu ft not the 18 I stated previously. Smaller than my smallish bins. Generally, the smaller the bins the harder it is to get heat. Should only mean a little more care with somewhat lesser temperatures. Doable but I would want something larger. Classic minimal dimensions are 3 x 3 x 3. You can do that with pallets.
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jpcvb, you collect a years worth of rain water in a container? In so cal? Must be a huge container? Hats off. Earth Machine? That would retain moisture better and strikes me as a good basic digesting machine when the worms kick in. Can't imagine getting any heat but with enough worms you don't really need or want that do you?
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