A compost pile. Some rights reserved by hardworkinghippy.

If you garden, you need to compost. It’s easy, too. This post will examine what and how to compost. But first, let’s look more generally at what composting is.

We humans didn’t invent recycling. We learned it from nature. The natural lifecycle begins with plants. Animals eat plants, either directly or indirectly by eating other animals.

Eventually, everything dies. Trees and bushes that live a long time shed their leaves every year. All that dead stuff rots, which only means that something else eats it. All kinds of microbes break it all down. So do some kinds of insects—and worms. Think of compost as worm poop, except it’s not as disgusting or unsanitary as other poop.

In simpler times, people would just toss food scraps on the ground somewhere. Rats, crows, cockroaches, and the like would feast on it while the microbes and worms did their work. Nowadays, we can’t just let leaves, food scraps, and all just lie around on the ground. There are too many of us too close together. We don’t want critters close by digging through it, either.

Eventually, we invented the sanitary landfill. Once the waste gets buried there, there is no air. It can take decades for organic matter to rot in those conditions. Bacteria that live in airless conditions produce methane, a potent greenhouse gas. Landfills are America’s third largest source of methane.

For that reason, most if not all jurisdictions forbid sending yard waste to the landfill. They compost leaves and turn tree branches into mulch.

Because composting uses air, it produces carbon dioxide instead of methane. And it doesn’t count in calculating greenhouse gases. Nearby plants can handle it all.

Some principles of home composting

A few things you can’t compost

Cooking in fat. Public domain from Max Pixel

In principle, you can compost any kind of organic material. But you don’t want your dogs or any wild animals rooting through your compost pile looking for bones and meat scraps. So don’t put any foods from animals in your compost. That includes not only meat, bones, and fat, but also cheese and other dairy products.

Also, don’t try to compost fats, oils, and grease even if they come from plants. For one thing, it takes way too long for it to break down. It also repels water, and the composting process requires plenty of water. For that matter, don’t pour any kind of fat, including salad dressing, down the drain. It must go in the trash.

Don’t compost weeds or diseased plants, either. Composting may not rot the seeds or kill whatever causes the disease. Commercial composting equipment can handle them, so put them at the curb with your yard waste—even if you compost most of it.

If you have a chipper for tree branches and shrubbery trimmings, put them in your compost, but if not, they will take too long to decompose. Otherwise, put them out for your municipal yard waste collection.

I have seen recommendations not to compost rhubarb or walnuts. They contain possibly harmful chemicals.

A lot of things you can compost

My compost bucket

So what can you compost? Begin with leaves and grass clippings, but don’t stop there.

Collect food waste in a container in your kitchen and add it to the compost from time to time. Things like apple cores or banana peels are obvious, but don’t forget egg shells, tea bags, and coffee grounds. But don’t stop there, either.

Most people who are really dedicated to environmental causes avoid paper napkins, towels, and plates. But if you use them, compost them, even if they have some grease on them. A little won’t hurt. If you have your own paper shredder, put the shreds in your compost instead of the trash. You can also add newspapers and other paper—but not glossy paper like magazines.

What about the clothes you wear out or other scrap fabric? I mean things too ratty for anyone to wear. You have two better choices than putting them in the trash. Good Will and other thrift shops accept them for textile recycling. Or, since this post is about composting, you can cut or tear it into small pieces and add them to your compost.

And don’t forget hair—yours or your dogs’. Or even fingernail clippings. If you have a wood fireplace, compost the ash. If you use a saw, compost the sawdust. Basically, you can compost anything organic provided it isn’t mentioned in the previous section. The more you compost, the less gets hauled off to the landfill.

Methods of composting

Highpoint community garden, West Seattle. Public domain from Wikimedia Commons

For the purposes of composting, you have only two categories to keep track of. “Green” material, such as food scraps and grass clippings, contains a lot of nitrogen. “Brown” material, such as paper, dry leaves, or wood chips, contains lots of carbon. A good compost pile needs both, probably with about three times as much brown material as green.

If your compost pile starts to stink, it has too much green material. It should eventually become hot. If it doesn’t, it needs more green material. I’ve seen compost starters for sale, but you don’t need them. Just mix a little completed compost in with the fresh material to provide enough microbes to start the process.

Most instructions for composting say to alternate layers of green and brown material and water each layer. With most methods, you’ll have to turn the compost, and that will destroy the neat layers. Turning it lets it all heat up. It makes sure there’s plenty of air throughout the pile.

If you want to be really fancy, and want compost in a hurry, you can buy a tumbling composter. Don’t fill it completely. You will have to turn the tumbler frequently. The amount of compost you can make is limited by the size of the tumbler. It doesn’t much matter where you put it, although a shady spot is probably best.

You can buy or make a composting frame. Again, prefer a shady place for it. The compost will still sit directly on the ground so worms can get to it. You will need to water it and turn it with a pitchfork from time to time. The walls of the frame will be inconvenient for turning, and this method is the slowest of all. The lid will discourage critters from digging through the compost.

More simply, you can just make a large pile of stuff. In that case, it has to be in a place where it will get rain, but on high enough ground that excess water drains off. It must be out of direct sunlight so it doesn’t dry out. You ought to turn it regularly, although I confess I don’t.

Simplest of all? Bury it somewhere where rainwater doesn’t pool and then forget it. Well, don’t forget where you have already dug. You don’t want to dig up the same place before everything decays. But the worms will see to admitting plenty of air.

If you bury material in your garden, you can plant in those places when composting is complete, without having to carry it from a pile to the garden. You can follow a procedure called trench composting. My dogs don’t dig in the yard. Your mileage may vary.

Depending on whatever method you use and your local weather conditions, allow three to twelve months for all this material to become usable compost.