Cottonwood Firewood

I'll say something controversial, cottonwood gets a worse reputation than it deserves. Yeah, the BTU output is low. Yeah, green cottonwood is basically a sponge. But if you're in the Midwest or the Western plains where hardwood options are slim, cottonwood might be the most available firewood within 50 miles of your house, and free wood is free wood.

At 12.6 million BTU per cord, it's down near the bottom of the firewood BTU chart, no getting around that. But here's a number that tells the real story: a green cord weighs 4,640 lbs while a dry cord is only 2,040 lbs. That's over 2,600 lbs of water per cord. More than half the green weight is moisture. So when people say "cottonwood doesn't burn" they usually mean "I tried to burn green cottonwood," and yeah, that's basically trying to light a wet towel on fire.

The good news is cottonwood splits like butter. Straight grain, soft wood, one swing and done. Even big ugly rounds with some twist to them usually come apart without much fight. It produces medium smoke and few sparks, so it's well-behaved in that department. Coals are actually rated good in our data, which surprised me honestly. Once it's dry and burning hot, it does hold a coal bed better than you'd expect for such a light wood. The fragrance is slight, not offensive, not memorable. Some people say green cottonwood smells sour. They're not wrong.

Seasoning time is 6 to 12 months, which is a plus. Get it split and stacked by spring and it's burnable by fall. The key with cottonwood is getting it off the ground and getting air moving through the stack. It's prone to punking out if it stays damp, so don't just toss it in a pile and forget about it. Elevate it, cover the top, leave the sides open.

Here's the bottom line on cottonwood. It's a fair-rated firewood that fills a real niche. It's abundant, it's easy to process, and it seasons relatively fast. If you're comparing it to Quaking Aspen firewood, they're in the same ballpark, light, soft hardwoods that burn quick and work best as supplement wood. Mix it with something denser if you've got it. Burn it alone if you don't. Either way, don't leave it sitting green and then blame the species.