How To Compost

The average household throws away about 25 percent of its food. But if we composted that stuff, we would lighten landfill loads while creating nourishment for gardens and lawns. Cary Oshins, a soil scientist and the director of education for the United States Composting Council, explains the easy, earth-friendly practice.

How do you start?
Get a bottomless plastic, metal, or wooden container that holds about 300 litres (you can buy commercial composters at garden centres). On the kitchen counter, set a small lidded containerfor catching compostables as you cook.

What foods can go in the compost bin?
Fruit peels, coffee grounds (and paper filters), eggshells, leftover vegetables. Don’t compost meat, cheese, or fish, because they attract animals. And skip cooking oil, which draws insects.

What else?
Any and all organic matter. Most of your compost should be made up of dry materials, like torn-up newspaper, twigs, dead leaves, and paper plates. These items contain carbon, which gives the microbes that decompose the pile the energy necessary to work their magic. Food and other moisture-rich items, like grass clippings, supply the protein that microbes need to reproduce. You’ll get the best results with a roughly three-to-one ratio of dry to wet. No worries if it’s not perfect; composting is very forgiving.

Is there any upkeep?
Watch the moisture level. The pile should be damp, like a wrung-out sponge—not soaking, like a swamp, or dry enough to blow around. If it’s too dry, spritz it with the hose. Too wet? Add shredded newspaper or wood chips.

What about the smell?
Maintain a thick layer of dry stuff, like dead leaves, at the top of the pile, and cover new food scraps with old compost. (Have a small shovel handy for this purpose.)

How can you tell when a pile has decomposed?
It usually takes four to six months for compost to turn into dark brown or black soil with a nice, earthy aroma. Once most of your pile fits this profile, take away the bin and let the finished compost continue to break down in your yard for a few weeks. Put the bin in a new spot to start a fresh pile. Kick it off by scooping in anything from the old pile that’s not quite decomposed.

What if you don’t have any outdoor space?
You can still recycle food scraps if you have somewhere to unload them weekly. Check with your local farmers’ market to see if there’s a drop-off site. In between hauls, stash scraps in the freezer in a sealed container lined with newspaper.

Finally, how can you use compost?
Think of it as food for dirt. Spread it over your lawn to nourish the grass, or mix it into garden soil.