Composting 101: Turn Kitchen Scraps into Garden Gold

Compost is the closest thing gardening has to a free lunch: kitchen scraps and yard waste that would otherwise go in the trash turn into the single best soil amendment you can add to a garden, raised bed, or container. It doesn't require a science degree or expensive equipment — just the right ratio of materials and a bit of patience.

The two ingredients that matter

Everything in composting comes down to balancing two categories:

Greens (nitrogen-rich): kitchen scraps, coffee grounds, fresh grass clippings, vegetable peels
Browns (carbon-rich): dried leaves, cardboard, straw, shredded paper, twigs

The rough target ratio is 1 part greens to 2–3 parts browns by volume. Too many greens and the pile turns slimy and smells; too many browns and it barely breaks down at all.

What to actually put in

Yes, compost these:

Fruit and vegetable scraps
Coffee grounds and filters
Tea bags (check they're not plastic-lined)
Eggshells (crushed, they break down faster)
Dry leaves, straw, shredded newspaper
Grass clippings (in moderation, mixed with browns)

No, keep these out:

Meat, fish, dairy, and oily foods — they attract pests and smell as they rot
Diseased plants — pathogens can survive the composting process and spread back into your garden
Pet waste from cats or dogs — can carry pathogens unsafe for food gardens
Weeds that have already gone to seed — many seeds survive home composting temperatures

Choosing a composting method

Open pile — cheapest option, works fine if you have space and don't mind the look
Enclosed bin — tidier, keeps pests out better, good for smaller yards
Tumbler — fastest turnaround since it's easy to aerate by spinning, best for small households
Worm bin (vermicomposting) — works indoors or in small spaces, ideal for apartments and balconies with no yard at all

Getting it to actually break down

Chop larger scraps — smaller pieces decompose faster than whole items
Turn the pile every 1–2 weeks — this adds oxygen, which speeds decomposition dramatically and prevents bad smells
Keep it as damp as a wrung-out sponge — too dry and decomposition stalls; too wet and it turns anaerobic and smelly
Give it size — a pile at least 3x3x3 feet holds heat better and breaks down faster than a small scattered heap

How to know it's ready

Finished compost is dark brown, crumbly, and smells like rich earth — not like food scraps or ammonia. Depending on method and attention, this can take anywhere from 2 months (actively turned, chopped small) to a year (left alone in a cool climate).

Using it once it's done

Mix finished compost into garden beds, containers, or raised beds at planting time, or use it as a top dressing around established plants. There's rarely such a thing as too little compost — even a thin layer worked into the top few inches of soil noticeably improves structure and nutrition.

Composting turns what would be waste into exactly the soil boost your next planting needs — and if you're tracking a DIY garden or raised bed on GrowLocal, logging when you refresh a bed with fresh compost in your crop diary makes it easy to see which seasons your soil actually needed it.