I'm new to composting. We have an aerobin enclosed composter. I've run out of leaves and newspaper recently so I'm looking for more brown matter. My husband has a bunch of fir shavings from his wood planer. Can I use those in the compost as brown matter?
Agreed, yes you can. My friends compost large amounts of planer chips--ponderosa pine and douglas fir--in larger piles with lots of horse manure and some kitchen scraps. They get fine compost out of it. There are various lists of the carbon-nitrogen ratio of various ingredients. Sawdust and woodchips (planer shavings aren't usually listed) are higher on the carbon end, beyond newsprint which is more carbon rich than dried leaves. So to reach the ideal ratio, if that's your goal, you'll need to use less shavings than you would leaves, or come up with more high nitrogen items to balance them out. Or wait longer for the finished product.
I'm in the foothills of the San Pedro Mountains in northern New Mexico--at 7600' with about 15" of precipitation, zone 4b historically--growing vegetables for the local farmer's market, working at season-extension, looking to use more permaculture techniques and join with other people around here to start and grow for farmers markets.