It's the season for burning crapwood. During the colder heating months, I burn seasoned ash, oak, maple, beech, yellow birch -good solid hardwoods.
This time of year it's cool enough to run the stove, but it doesn't have to work very hard. This is when I'll burn some softwood, white birch, aspen, and any wood that's a bit punky or half rotted. Wood like that doesn't put out the BTUs of good wood, but those BTUs aren't needed yet.
The big downside of burning crapwood, especially with the woodstove's damper turned way down, is the chance of creosote buildup. The chimney has to be watched closely, and cleaned as needed. It'd be embarrassing if a retired Firefighter like me had a chimney fire.
Some people are real firewood snobs. They'll burn nothing but the best. Seems like a waste to me. I hate to let any sort of firewood go to waste. It's just a matter of knowing when and how to use it.