What to Put in a Compost Bin: Complete Ingredient Guide

Overview

Compost is a premier organic soil amendment—improves fertility and texture. Mixing into top 8 inches transforms garden soil. It's a blend of recycled garden, yard, and household waste decomposing into dark, crumbly humus. Free fertilizer built in layers using moisture and oxygen to generate heat for rapid decomposition.

How It Works

Best piles layer nitrogen-rich (green) and carbon-rich (brown) materials equally, moistened. Minimum 3 feet high for heat. Turn if cools. Fork-turn one forkful at a time. Frequent turning = 2–6 weeks; never turned = 6–12 months.

Green Materials (High Nitrogen)

Vegetable scraps, grass clippings, fallen leaves, soft trimmings, weeds, fruit peels, corn husks, carrot tops, eggshells, seaweed, spent forced bulbs, dead annuals. Farm manures (chicken, rabbit, cow, horse). Spent crops (bolted lettuce, finished pole beans).

Brown Materials (High Carbon)

Woody: leaves, finely shredded bark. Farm bedding: straw. Newspaper, coffee grounds.

Caution Items

Fish/shellfish scraps: high nitrogen but attract scavengers—bury deep. Weedy seed heads: spread weeds—avoid. Autumn leaves, twigs, wood chips: slow breakdown—shred or separate pile.

Never Add

Fat, bones, meat (scavengers). Human/dog/cat feces (pathogens). Diseased/infested plants (bury/burn). Colored paper/magazines (toxic inks). Plastics (don't decompose). Herbicide-treated grass. Black walnut, eucalyptus, cedar refuse (inhibit growth). Poison ivy/oak/sumac. Coal/charcoal ash (toxins).

Expert Tips

Chop large pieces small for speed. More greens if pile won't heat. More browns if smelly. Always turn to add oxygen and reheat when problems arise.