Composting 101

Whether you live in a country cottage with a strawberry patch the size of an Olympic pool or a high-rise city apartment with flowerpots for a garden, the time to start composting is now. Yes, it’ll make your garden happy, but it also has a double environmental payoff: Composting keeps waste out of landfills, and it fertilizes without chemicals. In other words, it isn’t just for you—it’s for all of us.

But what the heck is it? “Composting is simply the process of breaking down plant materials to form humus, a cakelike soil that’s so rich it’s basically the world’s best fertilizer,” says Gayla Trail, author of You Grow Girl: The Groundbreaking Guide to Gardening and creator of yougrowgirl.com. Just think of it as recycling, only instead of plastic bottles and aluminum cans, you’re recycling dead leaves and carrot peels.

There are many ways to create compost, including just heaping up dry grass clippings and leaves and letting the pile decompose (that’s passive, cold composting). But if you want to recycle kitchen scraps too, consider hot composting—mixing wet and dry waste in a bin, then occasionally turning the pile to aerate it, creating heat and accelerating the breakdown process. Even apartment dwellers can compost. If you don’t have a yard, you can try vermicomposting—that is, composting with worms (not icky ones, and no, they won’t take over your apartment!). 

If you choose to go hot, here are the basics: Put your bin in a level, shady spot, then add a few inches of brown material, then a thin layer of green material and finish with a thin layer of brown. Next, sprinkle the compost with water so it’s damp, but not wet, like a wrung-out sponge. Stick to the “two parts brown to one part green” ratio when you add to your pile, and always finish with brown on top.

Finally, you’ll need to turn your bin. You can do this as often as every few days or as little as once a month, but the more you do it, the faster it will “cook.” In about six months, you’ll find a brown, earthy mixture at the bottom of your bin—homemade compost!

Worm Power
With vermicomposting, “beneficial bacteria break down kitchen waste into little packages for the next guys in the food chain—the worms—to eat,” explains Alane O’Rielly Weber, creator of wormlady.com and an instructor for the Master Composter Program of San Mateo County, CA. The worms in turn give you rich, moist, odorless compost.

For this job, you need a particular type of worm called red wigglers, sold at garden centers, bait shops or online. Once you get your worms, tear newspaper into strips and cover the bottom of your bin, then sprinkle water on it till just damp. Next, add the worms with the earth they came in and put your covered bin in a cool, dry, dark place (under your kitchen sink or in the basement—anywhere that won’t freeze or get too hot) and ignore it for a day or two.

Then it’s feeding time! Cut fruit and veggie scraps into one-inch pieces and bury them in the dirt in one corner of your bin. A few days later, bury more food in an adjacent corner. Keep rotating corners; by the time you get to the fourth, the food in the first should be almost gone. As you add scraps, always rotate and bury. After a few months, you’ll notice a lot less newspaper and a lot more brown, crumbly stuff in your bin. That’s your compost. To harvest it, push all the contents of the bin to one side. Lay down new newspaper on the other side, then bury food scraps under it. After a week or so, the worms will all migrate to that side, leaving the compost on the other side, ready to scoop up.

Note: Avoid garlic, lots of onion and anything spicy or salty, as they can poison worms. And keep in mind that every few months the worms will have cute worm babies. Worms restrict their breeding to match the food available and the size of their bin, so overcrowding is unlikely. If you do feel like you have extra worms, don’t liberate them to the outdoors (they can’t tolerate cold temperatures); donate them to an elementary school or greenhouse.