Browns and greens

Which is which

Browns: dry leaves, shredded cardboard, paper, straw, woody prunings, sawdust from untreated wood, egg boxes.

Greens: fruit and vegetable scraps, grass clippings, coffee grounds, tea leaves, fresh plant material, manure from herbivores.

Colour is a memory aid, not a rule, and it misleads constantly. Coffee grounds are brown and behave as a green. Fresh green prunings are a green; the same prunings dried for a month are a brown.

The test that actually works

Is it wet and soft, and would it rot on its own in a bag within a week? Green. Is it dry and structural, and would it sit unchanged in a bag for a year? Brown.

What the ratio really means

Roughly equal parts by volume. You will read “30:1”. That is a carbon-to-nitrogen ratio by weight, which is a laboratory measure, not something you can eyeball. See carbon-to-nitrogen ratio if you want the detail.

Reading the pile

Smells sour, looks slimy, matted: too many greens. Add browns and turn.

Dry, nothing happening, looks the same as last month: too many browns. Add greens and water.