Great For Furniture, Lousy For Heat
We are now firmly into the wood-stove-heating season, and it happens that this year we have a lot of black walnut to burn. Not anything furniture-worthy, I set all that aside for use in the shop later, but the branches and such. Since we felled several walnut trees two years ago there is a lot of that “clean up” to burn, and burn it we are. One thing is clear in my observation — walnut may be great for furniture making and bowl tuning, but as a firewood? Meh.
For the number of BTUs per unit volume of wood it really fails to deliver. Yes, of course it burns and provides heat as a result. But compared to everything else on the menu for wood burning it falls way short. Plus, it is really ashy, as bad as soft maple.
In fact, walnut comes in dead last in my hierarchy of firewood I can harvest from my own ~70 acres of forest.
The top of that list is occupied by locust, which seems to be almost as BTU-dense as the coal I burn in the shop stove. It can’t be, of course, but goodness I love the output of heat vs. volume and ash I get from locust. I’ve got a lot of it including two stupendous fallen trees up near the ridge property line near the cabin. Even one of those trees will suffice for a complete winter, so I am anxious to bush-hog enough to get my little 4WD truck right up to the windfall. In fact, the two remaining standing trunks are so big I need to hire my pal Bob to come and bring them down. I just do not possess the experience, skill, or saw to bring them to the ground.
Next comes oak, which we have a fair bit of but not as much as locust (firewood-wise). Given the amount of windfall of other species we have up the hill I do not cut much oak. But when I do, once seasoned it is a premium source of heat.
As is ash, of which I have very little. The characteristic of ash that makes it a good firewood is that it needs almost no seasoning to be ready for the woodstove.
Cherry and maple are also good source of heat, and we have a lot of both. The difference between them is that maple is a lot more ashy than cherry for the amount of heat provided. When we burn a lot of maple we have to clean out the stove about once a week. With cherry it would be every two weeks. For oak and locust it could be every three weeks. About equal to cherry is the surprise pick of black birch, which we get a tree or two every so often.
We do not have any tulip poplar so the last spot is occupied by black walnut. It’s just the way it is. We’ve got a very large walnut tree that is ailing and through which the power and phone lines travel. I hope the tree recovers, but if not there’s a huge pile of lousy firewood waiting to happen.
BTW I am almost done splitting and stacking the firewood for next winter and will likely wrap that up with a couple of good days after New Year’s and will weave more occasional firewood processing into my routine thereafter. A couple hours here, a couple hours there, and the mountain of cut wood will turn into a mountain of split and stacked wood.
Osage Orange aka monkeyball trees rival black locust for heat.Honey Locust are no where near as hot as the Black Locust. Honey Locust is a nice wood, somewhat like a harder elm for woodshop use.