What Goes in Good Compost: Greens, Browns, and the Secret Ingredients

Great compost isn't magic—it's a balanced recipe. Master the green/brown ratio, avoid the no-nos, and you'll produce dark, earthy humus every time.

The Core Formula

2–3 parts Brown (Carbon) : 1 part Green (Nitrogen) by volume.

Greens (Nitrogen-Rich, Moist)

• Vegetable/fruit scraps, peels, cores
• Coffee grounds & filters, tea bags
• Fresh grass clippings (thin layers!)
• Green plant trimmings, deadheaded flowers
• Weeds (NO seed heads)
• Seaweed/kelp (rinse salt)

Browns (Carbon-Rich, Dry)

• Shredded leaves (run mower over them)
• Straw, hay (seed-free)
• Shredded cardboard, newspaper (no glossy)
• Sawdust/wood chips (untreated only, thin layers)
• Pine needles
• Corn stalks, dried garden debris

Boost Additions (Small Amounts)

• Crushed eggshells (calcium)
• Manure: herbivore only (cow, horse, chicken, rabbit)—aged preferred
• Garden soil or finished compost (inoculant)
• Rock dust, kelp meal (minerals)

Strictly NO

• Meat, fish, bones, fat, dairy
• Dog/cat/human waste
• Diseased/infested plants
• Weeds with seeds, invasive roots
• Charcoal ash, lime (alkaline—slows process)
• Glossy/coated paper, stickers, plastic

Surprising Yes (If Processed)

• Dryer lint (natural fibers only)
• Vacuum dust (remove non-organic bits)
• Hair, fur, feathers
• Cotton/wool rags (shredded)
• Hamster/gerbil bedding (paper/wood based)

Process Management

• Moisture: Wrung-out sponge. Squeeze handful—1–2 drops.
• Aeration: Turn/tumble weekly (tumblers) or fork (bins).
• Temperature: 130–150°F = active. Turn when cools.
• Done when: Dark, crumbly, sweet earth smell, unrecognizable inputs.

Troubleshooting

Composting is forgiving. Observe, adjust, and the microbes do the work.

Symptom	Fix
Smelly (ammonia/sulfur)	Too wet, too much green → add browns, turn
Dry, not breaking down	Add water + greens, turn
Flies/maggots	Bury food deeper, cover with browns
Cold pile	Too small, wrong ratio, dry → rebuild