Garden chart
Compost Carbon-to-Nitrogen Ratio Chart by Material
A compost pile breaks down fastest around a 25-30:1 carbon-to-nitrogen ratio overall. 'Greens' (nitrogen-rich, often wet) and 'browns' (carbon-rich, often dry) are the shorthand gardeners use, but the actual ratios vary a lot within each category — this chart gives real numbers instead of just the green/brown label.
| Material | Approx. C:N ratio | Category |
|---|---|---|
| Fresh grass clippings | 15-20:1 | Green |
| Vegetable scraps | 15-20:1 | Green |
| Coffee grounds | 20-25:1 | Green |
| Fresh manure (chicken) | 7-15:1 | Green |
| Fresh manure (horse/cow) | 20-25:1 | Green |
| Fallen leaves (dry) | 50-80:1 | Brown |
| Straw | 75-100:1 | Brown |
| Shredded cardboard/newspaper | 150-200:1 | Brown |
| Wood chips/sawdust | 200-500:1 | Brown |
| Pine needles | 60-110:1 | Brown |
Notes
- In practical volume terms (not weight), this works out to roughly 1 part greens to 2-3 parts browns for most home piles.
- Too much nitrogen (excess greens) makes a pile slimy and smelly; too much carbon (excess browns) makes it break down very slowly.
- Woody material like sawdust and wood chips breaks down so slowly that it's often better used as mulch rather than mixed into an active compost pile.
Put this into practice
- Composting CalculatorWhat ratio of greens to browns does my compost need?
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- Seed Sowing Depth Chart by Vegetable and FlowerHow deep to sow common vegetable and flower seeds directly in the garden, plus days to germination as a rule of thumb.
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