Composting — Build Michigan's Best Soil
Compost is the single most important input in any Michigan garden. It loosens clay, adds moisture retention to sand, feeds soil biology, and delivers a slow-release fertilizer that synthetic products simply cannot replicate. And the raw materials — kitchen scraps and garden waste — are free.
What to Compost — Michigan Materials Guide
| Material | Brown (Carbon) or Green (Nitrogen)? | Michigan Availability | Notes |
|---|---|---|---|
| Fall leaves (maple, oak) | Brown — high carbon | Abundant September–November | Michigan's #1 compost ingredient. Shred first for faster breakdown. Bag and save excess for year-round use. |
| Grass clippings | Green — high nitrogen | April–October | Add in thin layers only — thick layers mat and go anaerobic. Excellent activator for slow piles. |
| Kitchen vegetable scraps | Green — nitrogen-rich | Year-round | Core ingredient. Bury under browns to prevent odor and deter pests. No meat, dairy, or oily foods. |
| Coffee grounds | Green (despite brown color) | Year-round | Michigan gardeners can collect from local coffee shops — many give them away free. Excellent for blueberries directly. |
| Straw (not hay) | Brown | Available at Michigan farm supply stores | Excellent structural carbon. Hay contains weed seeds — avoid. Clean wheat or oat straw only. |
| Cardboard (uncoated) | Brown | Year-round (free from stores) | Break into pieces; removes slowly but valuable carbon source. Also excellent as bed liner under raised beds. |
| Wood chips | Brown — very high carbon | Free from tree services (ask!) | ArborChip and local tree service companies often deliver free. Best as garden mulch; add small amounts to compost. |
| Garden plant debris (disease-free) | Varies — mostly green | All season | Chop small. Do not compost diseased material — Michigan's humid summers spread fungal disease through compost. |
Build Your Compost System This Weekend
- Choose your system
The simplest: a 3×3×3 foot wire or wood bin (cost: $0–$30 from salvage materials). Michigan winters slow decomposition but don't stop it — an insulated pile or three-bin system keeps working through December.
- Build the base layer
Start with 4–6 inches of coarse browns (wood chips, straw, or shredded cardboard). This creates airflow at the base and prevents a soggy, anaerobic mat at the bottom.
- Layer greens and browns 1:3
One part nitrogen-rich greens (kitchen scraps, grass) to three parts carbon-rich browns (leaves, straw, cardboard). This ratio feeds microbes at the right pace. Imbalance toward greens causes slimy, smelly compost; imbalance toward browns causes slow, dry piles.
- Keep it moist — like a wrung sponge
Michigan's spring and fall often provide natural moisture; July–August may require adding water. Check weekly — squeeze a handful; a few drops should come out. Dry pile = stalled breakdown. Wet pile = anaerobic = bad smell.
- Turn every 1–2 weeks for hot composting
Turning introduces oxygen, which feeds aerobic microbes and raises temperature. A properly managed Michigan hot pile reaches 140–160°F, killing weed seeds and pathogens — producing finished compost in 6–8 weeks.