Compost problem

[hob]

Hi

I have been gardening for nearly 40 years, and two years ago I started a compost bin for my lawn clippings.

I have two bins - one is a cylinder made of garden wire, 4 feet across and stands about 5 feet high. The other is made of open-spaced planks and is 3 feet by 6 feet by 4 feet high.

Both were filled again last year, the rectangular one with primarily grass clippings across the year; the cylindrical one with about a 50-50 mix of finely shredded dropped maple leaves and grass clippings with a hand-held spread's worth of 10-10-10 every three inches of depth, watered to be sure it was moist around mid-September. They were turned once and twice last year.

This early spring, I go out in the cold and check, expecting them to be frozen solid, and they were loose and warm inside - they were busy cooking.

But now, a few weeks later, they are definitely cold and moist inside, and the mix still looks like partly moldy grass and leaf shred. It definitely isn 't dark compost.

Since the microbes had fertilizer, moisture, no packing down, and time, I would have expected more breakdown, or at least the mix to not be warm at the end of winter and then cold now.

Any ideas as to why they stopped working, and/or what am I missing and what should I change, if anything ?

[Doug Kanter]

It's supposed to be built up in layers. The grass bin, in particular, is a problem because a pile of just grass tends to seal its own insides, and you get anaerobic decomposition (relative absence of air). Re-mix it all, making alternating six inch layers of green & brown matter (dried leaves & stems), with whatever kitchen scraps you want to add within the layers. The brown matter is difficult at certain times of year, obviously, since you don't always have falling leaves. One way around this is to save surplus dried leaves in OPEN bags in the garage, so you have a supply to add later.

[John Wheeler]

I suspect it's anaerobic, because of lack of oxygen. How does it smell when you turn it? Frequent turning helps bring in oxygen and mixing up the ingredients. Layering by itself does little. Adding fertilizer that you pay for is mostly wasting money.

[Phisherman]

To keep a compost alive, it must be kept moist and fed a mix of green and brown layers. Turning it once a month is about right. If it smells, more brown material is needed. Your compost size is about right. Do add fertilizer.

[sherwindu]

Hi Hob,

Sounds like you have taken the proper steps to get your mulch pile working. I would guess it has shut down partly due to the cold weather. I would wait for the warmer Spring temperatures for it to get started again, keeping the pile moist. You may be rushing things a bit expecting to get the fully composted nice black stuff this early in the season. My guess is that the pile with the leaves and grass should work better than the straight grass pile. I have a similar mulch pile and it takes at least a year before it is fully cooked. I say be a bit more patient.

Sherw> Hi

[hob]

Thanx for the input - some more background - It was not "sealed" this year - I had had that the previous year where too much "just grass" made it "heavy" and sealed it, as you say. So I kept if from packing down when I put the mower's bagfuls in, and I mixed in some of the previous year's dried shredded leaf I had kept in bags for mulch, etc (my mower shreds dried leaves into bits about half the size of a dime). And being in the garden cloth seems to keep it from getting soggy.

I did not layer it per se, as it was mixed with a pitchfork about once a month.

Re-mix it all, making

[hob]

Sweet and a little moldy -

Thanx for the input - some more background - I had the smell the previous year where too much "just grass" made it "heavy" and sealed it. So I kept if from packing down when I put the mower's bagfuls in, and I mixed in some of the previous year's dried shredded leaf I had kept in bags for mulch, etc (my mower shreds dried leaves into bits about half the size of a dime) to keep it form packing. And being in the garden cloth seems to keep it from getting soggy.

It was mixed with a pitchfork about once a month.

Frequent turning helps bring in oxygen and mixing up the

FWIW - I got that fertilizer thing from the extension service's bulletin on making compost bins, and from the garden show.

[hob]

Thanx for the input - I watered both bins today, in case they lack sufficient moisture. I'll see if that helps.

[hob]

That was the odd part - it was active and warm inside the piles in late February, and cool inside them in early April. (Mpls)

I would wait for

I did water the bins today, on the chance they were not damp enough.

I had heard it took a few months - the grass bin has been there and added to (no chemicals on the grass) since the first mowing of last spring. And a lot of it now looks like dried grass with powdery white mold.

My guess is that the pile with the leaves and grass should

I would have thought so, too - but the opposite seems to be the case - the cylindrical bin has the roughly 50-50 mix of leaves and grass from last fall and I think the bottom even has some from the previous fall, and it isn't "as far along" as the rectangular bin which is mostly grass. Thus my thinking some more water might help.

I have a similar mulch pile and it takes

It's either patience .... or having mulch rather than compost.

thanx for the advice

[John Wheeler]

Fertilizer should only be added if you know your compost pile has a very high carbon to nitrogen ratio. With the amount of grass you're using, surely you have enough nitrogen. Be careful with water. Too much can make it very difficult for your pile to get oxygen and it will go anaerobic. I'd add a little at a time to see if it makes the pile heat up. I keep my piles on the dry side and they do great. I've never added fertilizer. My "green" (i.e., high nitrogen) material comes from household kitchen waste and lots (15 pounds a day) of coffee grounds from Starbucks. I get more coffee grounds than I can compost, so I just add the extra directly to the yard. Smells good.

John Henry Wheeler Washington, DC USDA Zone 7

[George.com]

I think the have patience bit is the key here. Unless you desperately need the compost leave it another few months and just observe what happens. You can turn it as others have said or you can simply leave it and see what develops. Some compost makers are paranoid about anaerobic decomposition (lack of oxygen) and tell you to constantly turn and turn your pile to encourage aerobic composting. Anaerobic breakdown will give you good compost through it will take a time. It won't kill weed seeds (a hot compost will) but that is a problem depending on what you put in the compost. Leave it for a while longer and nature will likely do a decent job. A good rule of thumb, as far as I am concerned, is check for worm life. If there is a good build up of worms (apart from the very hot centre) indicates things are breaking down.

rob

[bamboo]

Mix in some shredded leaves, you have a mower run some over, turn it and keep it moist. Don't worry about layers it composts much better when mixed. It's done when none of the original ingrediants are recognizable. Straight up grass clippings pack down and go anaerobic after the initial heating and stinking phase where they offgas ammonia.

[David E. Ross]

My compost is primarily brown matter: leaves from oak, ash, liquidambar, and zelkova. The only fertilizer that I add is high-nitrogen: urea (in very small amounts).

I had a great compost pile, just a mound against a corner of a block wall. When I had new landscaping installed, the contractor tried to do me a favor by cleaning up my yard. Not only did he remove all the leaf mulch from my camellias, but he also removed my "mess" -- my compost pile. Since then, I learned to always advise contractors to leave the mulch and compost.

It took about 14 months for a new compost pile to finally produce a good compost (actually a form of leaf mold). Now, however, I keep some of the old compost in the pile when I add more leaves. This ensures that the necessary micro-organisms are present. The time to compost should now be about 6 months.

[Jim Voege]

Are both your piles in full sun? I compose in fairly heavy shade and I don't expect this year's additions to be ready until next year. The amount of sunlight on the pile makes a big difference.

Jim

[Jim Voege]

While generally true that is not always the case. If circumstances are such that you have too high a proportion of carbon (brown) to nitrogen (green) a bit of relatively inexpensive spring lawn fertilizer can redress the balance.

Jim

[Andrew Ostrander]

My thought about why your pile is cool now but was hot earlier is that all the easily digested food has been used up, and the microorganisms are not able to consume the remaining food fast enough to keep the pile warm. It will turn to compost or leaf mold if you keep it moist and wait.

[hob]

They are in the shade - deep shade. I wondered about that, but since the piles make their own heat which would increase bacterial activity, I thought it wouldn't be a major factor.

[hob]

That makes sense and was kind of my thought - but I also thought that if their food was gone, would the stuff in there now was all that there would be unless I did changed something- i.e., all I'd get was light brown plant matter rather than dark brown compost.

Perhaps there are several varieties of microbes, and some (the finishers, hopefully) don't do as well in the cool weather?

It

[Doug Kanter]

It makes a huge difference, although I think it's not so much in how well it composts in warm weather. Rather, it determines whether the pile is frozen or defrosted in winter. My compost box was full in early December last year, and normally, I wouldn't have expected any action from it until it defrosted in March or early April. But, it's been a mild winter, the box is in the sun for most of the day, and when I checked it in mid-March, its volume had reduced by half. Next year, it might not be that way.

[Andrew Ostrander]

Yes, I agree. I expect there are many type of microorganism in there, some of which operate faster than others. Also the slowdown can be because the food is now more spread out and it takes longer for a microbe to find it, and because the microbes now also have to deal with being surrounded with their waste products.