How do I get leaves to turn into mulch or compost?

November 12, 2004 9:45 AM

I have a humongous pile of leaves in a corner of my back yard, that had been building up for about three years now. It is nearly four feet high and occupies about 15 square feet. I thought it would automatically turn into mulch, but this doesn't seem to be happening. None of the mulch or compost-related sites I've googled seem to deal with a leaf pile of this unwieldy size and bulk. How can I make this monster disappear into something that looks and acts like dirt?
posted by Faze to Home & Garden (16 answers total)

can you burn it? or maybe rent a mulcher/chipper and start chewing away at it.
posted by Hackworth at 9:52 AM on November 12, 2004

Composting generally takes effort to accomplish in a timely fashion. There have been previous threads on the subject here and here, with a different goal for each. Composting also works faster if the compost matter is broken down into smaller pieces. To accomplish the goal of setting up an active compost pile and reduce the size, I dunno, can you get your hands on an industrial paper shredder?
posted by Danelope at 9:54 AM on November 12, 2004

The thing about composting is that you have to mix in nitrogen (green stuff, kitchen scraps, etc.) with the carbon (leaves, etc.) in order to get the bugs and worms to do their job and turn your annoying pile into humus. Roughly, you need 2 parts carbon to 1 part nitrogen, and some moisture to get the decomposition process to start rocking.

I would start another pile where you move a small amount of leaves and add 1/2 again that amount of nitrogen rich material. Compost doesn't like cold or wet conditions, so if your climate is getting wintery, best wait until next spring.

Here's a little site with more info about composting... there are plenty more where that came from.
posted by maniactown at 9:59 AM on November 12, 2004 [1 favorite]

You could begin covering it with brush and eventually a nice raccoon or somesuch might take up residence and raise a family in it. Brush piles attract all kinds of wildlife, and a base of leaves seems to provide good insulation for the residents.
posted by Shane at 10:50 AM on November 12, 2004

Response by poster: I like the idea of feeding it into a wood chipper (I mean, this pile is HUGE). Once it's all ground up into little bits, I can imagine it being much more manageable. Then I can add some organic waste this spring, and according to these other suggestions, and let it decompose in private. (I'm mainly trying to avoid work.) Thanks for you help.
posted by Faze at 11:08 AM on November 12, 2004

Nitrogen is the key. Leaves on their own make awful compost because they lack nitrogen. If you stop adding leaves they will eventually form leaf mold and break down. This can take several years. Contrast that with being able to make compost in a little over a month with a high nitrogen source and the right conditions. Adding in grass clippings is the traditional suburban solution, and this will likely require a lot of grass clippings. Nitrogen rich natural fertilizers can also help, but the problem is that they will not really benefit whole leaves that much. If the leaves have been chopped-up then it can get at them and get things going. Mixing in some soil can help much in the same way as chopping the leaves - it is all in an effort to maximize contact of the leaves and nitrogen. Adding worms can also help, but again it works better when you have chopped leaves and some soil.
posted by caddis at 11:11 AM on November 12, 2004

I agree with maniactown and caddis: not enough nitrogen. And not enough air as the leaves compact from the weight. And as caddis points out, grass clippings, if available, help somewhat with the nitrogen. You can also buy "compost accelerator" which is high-nitogen fertilizer and compost ing bacteria. Or just use high-n fertilizer like cottonseed meal, blood meal, etc.

For this pile I'd recommend renting or borrowing a tiller, and a serious one with a lot of hp. It's going to be difficult to get the pile mixed with whatever you add to it and get air to the bottom of the pile. The tiller will do it but it'l be a lot of work.

In the future you can chop leaves with a lawn mower before adding to the pile. And mix in some nitrogen source as you go. And some old compost helps as well (provides some of those composting organisms). Building a pile atop a wooden shipping palette helps to keep air in the pile.

From my experience, a compost pile with just leaves will take about ten years before it's usable.
posted by TimeFactor at 12:02 PM on November 12, 2004

green stuff, kitchen scraps, etc.

In case it isn't clear the kitchen scraps cannot be meat or cheese.
posted by terrapin at 12:30 PM on November 12, 2004

Can you get a hold of horse manure to layer in? Horse manure is high in nitrogen and usually contains lots of red wriggler compost worms who'll eventually chew through your leaf layers.
posted by timeistight at 12:52 PM on November 12, 2004

how about dog waste? I read in one of the other threads that some people compost this. anything special to consider you composters out there?
posted by jacobsee at 1:10 PM on November 12, 2004

Just don't use dog- or cat-waste compost on a vegetable garden. Your home compost pile is unlikely to heat up enough to kill the pathogens in a meat eater's feces.
posted by timeistight at 1:18 PM on November 12, 2004

I compost my leaves in a pile. A new pile every year, unless I feel lazy. In Maine, it takes me about a year to compost a pile of leaves. The top and sides don't get done, so it looks like it's all leaves, but it's likely that at the bottom of your pile, you have compost, covered in the newer leaves. Turning it will accelerate the composting process. Use a pitchfork to move it to another corner. If it's really dry, add water.

I used to compost only leaves, but now that I add dogpoo, the compost is done faster. This compost is not nutritionally complete, but my flowerbeds don't care. Timeistight is right; no dogpoo compost on food gardens. I had some fencing, so I just made a circular leaf corral about 4 feet in diameter, 4 feet high. I fill it with leaves, and it makes compost. The pile gets smaller as the leaves boidegrade, so I keep adding leaves for several months.

The brown(leaves) : green(grass) ratio makes a big difference to the speed of composting, but Nature will kick in and compost will happen. You can even compost leaves in the plastic bags that the neighbors set them out by the curb in. The soil at my house used to be very poor, and now it's not bad.
posted by theora55 at 2:06 PM on November 12, 2004

Here's a discussion where some folks don't seem to be too concerned about the dangers of composting dogpoo. Sounds like it will contribute to the green/nitrogen part of the composting equation. I've got plenty of leaves so it sounds like I'm all set. I might try to make one of those in-ground jobs eventually...
posted by jacobsee at 2:36 PM on November 12, 2004

Do they sell dried blood or blood and bone meal in your neck of the woods? That's your N taken care of. Failing that, any squishy green stuff will do. And yeah, you'll need a lot. The usual advice is 7:1 greenstuff:woody matter.
posted by i_am_joe's_spleen at 5:31 PM on November 12, 2004

The shredder is a good idea because it reduces the size of your pile greatly AND the smaller leaf pieces make a tighter pile and in my experience they hold heat better.

One option is to go to Wal-Mart or a similar store and buy an electric leaf blower/vaccum. I have a Black & Decker model that I bought for very little and it works great for shredding if you do not have a chipper/shredder or do not know where to rent one. Mine has a 10 to 1 reduction ratio - basically ten bags of leaves becomes one bag.

I find the shredded leaves to make an attractive mulch as well, you could use it in flower beds if you have any. It goes away on it's own in the beds and enriches the soil.

Last year I shredded some leaves, some old newspapers, threw in a bunch of green lawn clippings, mixed it up a little with a garden fork, sprayed it down with water, and covered the entire mess with a tarp and put rocks around it to hold it down tight. The next spring there wasn't much left when I uncovered it.
posted by bargle at 8:54 PM on November 12, 2004

Response by poster: bargle -- that sounds like what I need to do. Thanks.
posted by Faze at 2:25 PM on November 13, 2004