Most guys in my area of Pa. wouldn't even handle birch. Wood is sold as hard wood, not soft stuff like pine, hemlock, birch poplar etc. Plenty of oak in my back yard, red and white. I, however, am cutting anything in my way which so far includes oak, pine, hemlock, ash, maple, white birch, cherry and even a bit of sassafras. Didn't believe the guys that told me " if it fits thru the door, it'll burn, but now I'm a believer. Its just a matter now of finding wood that wont burn, but it seems at this point it will be stuff thats falling apart in your arms.
** the sassafras smells really good when you cut it and light as a feather to handle. Obviously doesn't last long but its something to throw in the door..