C:N Ratio and Keeping Compost Moist in Our Climate
June 16, 2012
We are just starting to compost and I was wondering if in the southwest do we still use a 20/1 ratio of brown to green? And should we have an enclosed composter or will a fenced area work? My concern is the pile drying out.
Answer by WR: I think most recommend 25:1 or 30:1. But 20:1 or 40:1 also work. It’s hard to be exact anyway. I don’t think the C:N numbers in the southwest are particularly different than other parts of the country.
Of course, keeping compost moist is a big issue here in the southwest and an enclosed composter helps with that. But most of the composters I know here in Albuquerque use fence-type bins and often keep them covered with a lid or blanket or tarp. Check out Homemade Bins under Composting Info in our website main menu. If you can put your bin in the shade that really helps.
Also see our information about Desert Composting under Composting Info.
Answer by WR, Addendum: I just reread your question and see you asked about ratio of browns to greens (vs carbon to nitrogen). The ratio of browns to greens would depend on how much carbon or nitrogen are in the actual material you are using. Be sure to check out [Omar’s slides](http://docs.nmcomposters.org/carbon-nitrogen-ratio-simplified.pdf). The 9th slide talks about mixing greens and browns. But please don’t worry too much about these ratios. If it starts smelling bad, you probably have too many greens (or need to turn the pile). If it’s just sitting there not changing into compost, you probably have too many browns (or are not watering and turning often enough). I find that if I just throw in what I have available it works well nearly all the time.