Composting at home reduces what you send to the landfill and fortifies your garden.

It’s also easier than a lot of people think. In the end, it’s a simple formula:

Composting = Carbon + Nitrogen + Oxygen + Water + Time

+Carbon

The carbon part of that equation comes from what composters tend to call “browns.” This should make up the bulk of your compost pile—about 3/4 of it. It includes items such as:

• dry leaves
• prunings, twigs, and branches
• hay or straw
• mulch or wood chips
• sawdust
• old topsoil
• animal manure (no dog or cat feces; only animals that are herbivores)

+Nitrogen

The nitrogen in the equation comes from what are known as “greens” and should constitute about 1/4 of the pile. It includes:

• peels, cores, and seeds from fruits and vegetables
• coffee grinds
• eggshells
• green leaves
• grass clippings
• old VEGAN food (animal-based foods are fine for commercial compost pick-up, but not home composting)

+Oxygen

Oxygen is clearly just in the air, but to get it to work for your compost and help create the “heat” from the bacteria to break all those browns and greens into soil-enhancing compost. Adding oxygen is easy: turn, turn, turn. Turn your compost pile about once a week using a pitchfork or a shovel. This aerates the piles and helps keep everything moist.

+Water

The right proportion of browns and greens along with regular turning should keep your compost pile in good shape water-wise. If it starts looking too dry, you can add more greens; if it starts looking too wet, add more browns. If it seems really dry or it’s arid where you live, you may need to lightly water the pile every now and again. A healthy compost pile should seem about as damp as good soil or a damp-but-wrung-out dishrag.

+Time

It takes about 2 or 3 months for a healthy compost pile to go from a mess of stuff to something as precious as gold to gardeners. Serious composters may keep 2 or 3 piles going, so they always have a supply of the good stuff ready to add to their beds.

When space (or time) is a factor, add worms

Worms can speed things up and they can also make a smaller, greens-focused box compostable. A box with good drainage holes in the bottom filled with 8 to 16 inches of soil, old newspapers, and leaves topped with a solid layer of fruit and vegetable waste will become rich compost in a few weeks with the addition of some red wiggler worms.

What not to compost

What works in a home compost pile is different from a commercial one, where the heat generated by bacteria is much higher and can break down more items more quickly. At home, leave these items out of your pile:

• meat (mainly because it will smell and attract pests)
• fish and fish bones (ditto)
• shellfish or shells (ditto)
• whole eggs (ditto)
• dairy products (ditto)
• animal fats or oily products (harder to break down)
• cat litter
• dog or cat feces

How to get started composting

You can buy a box—or a tumbler to make “turning” the pile really easy—or build one with slats of wood at least 3 feet by 3 feet. You want some space between the slats so air can get in there (remember, oxygen is part of the equation). Start with a thick layer of browns such as twigs, dried leaves, hay, and/or straw. Then layer in greens and browns, always ending with a layer of browns on top.