Guide

Composting basics: turn scraps into soil

Food scraps and yard waste make up a large share of household garbage. In landfill they rot without oxygen and release methane, a powerful greenhouse gas. Composting turns them into a free soil improver instead.

The simple recipe: greens plus browns

• Greens (nitrogen): fruit and vegetable scraps, coffee grounds, tea bags (without plastic), fresh grass clippings.
• Browns (carbon): dry leaves, shredded cardboard and paper, straw, sawdust from untreated wood.

Aim for roughly two to three parts brown to one part green by volume. Keep the pile as damp as a wrung-out sponge and turn it now and then so air gets in.

What not to add to a home bin

Meat, fish, dairy and oily foods (they attract pests and smell), pet waste, diseased plants, glossy paper and anything with plastic. A city green-bin program may accept more - follow your local rules.

Options for every home

• Backyard bin or pile: the cheapest option; takes a few months.
• Worm bin (vermicomposting): works in apartments; red wigglers eat scraps quickly.
• Bokashi bucket: ferments scraps (including some meat and dairy) indoors; the result is buried or added to a compost pile.
• Municipal green bin or drop-off: no effort, and the program does the composting.

Troubleshooting

• Smelly? Too wet or too many greens - add dry browns and turn it.
• Not breaking down? Too dry or too cold - add water and greens; chop material smaller.
• Flies? Bury food scraps in the middle and cover with browns.

Using your compost

Finished compost is dark, crumbly and smells earthy. Mix it into garden beds and pots, or spread it as a thin layer around plants.