Ash lights fast, burns hot, and dries quicker than oak, but white, green, and black ash are not the same firewood. Here is how much heat each one puts out, how long it takes to season, and whether dead ash is still worth burning.
Yes, ash is good firewood. White ash puts out about 24.2 million BTUs per cord, close to red oak's 24.6, according to Utah State University Extension. It lights easily, burns hot, and dries faster than oak, maple, or hickory.
The catch is that "ash" covers more than one tree. White, green, and black ash burn differently, and a tree that has been dead for years is a different load of firewood than one cut live last week.
We run more ash through our kilns than any other wood. Here is what it actually does in a stove or fireplace.
Ash is one of the best all-around firewoods you can burn. It catches fast, burns hot, and makes very little smoke or smell once it is dry. For most people, it is an easy yes.
Where ash falls short is burn time. It will not last as long as oak, hickory, or hard maple, and its coals burn down sooner. That is where the "ash is overrated" opinion comes from.
The reason is weight. A cord is the same 128 cubic feet whatever the species, but a cord of air-dried white ash weighs about 3,472 pounds, while white oak weighs about 4,200. Less weight in the same space means less fuel to burn.
You can narrow the gap. Bigger splits and less air stretch an ash fire, and a few pieces of oak on top cover the overnight hours.
Here is how ash compares with other common firewoods, using air-dried values.
| Species | Heat per Cord (million BTU) | Air-Dried Weight per Cord (lbs) |
|---|---|---|
| White oak | 29.1 | 4,200 |
| Hard maple | 25.5 | 3,680 |
| Red oak | 24.6 | 3,528 |
| White ash | 24.2 | 3,472 |
| Birch | 20.8 | 2,992 |
| Cherry | 20.4 | 2,928 |
| Green ash | 20.0 | 2,880 |
| American elm | 20.0 | 2,872 |
White ash sits right next to red oak because the two woods are nearly the same density (basic specific gravity of 0.55 for white ash and 0.56 for northern red oak, per Penn State Extension). Green ash is a real step down.
You will see ash listed online at 25 to 28 million BTUs per cord. Even white ash, the best of the three, comes in around 24.
To see where ash lands against every other common species, check our list of firewood species ranked by heat.
Most ash firewood in the Midwest comes from three native trees, and they do not burn the same.
| Tree | Fresh-Cut Moisture | Heat per Cord (million BTU) | As Firewood |
|---|---|---|---|
| White ash Fraxinus americana |
46% heartwood, 44% sapwood | 24.2 | Excellent. The driest and densest of the three. |
| Green ash Fraxinus pennsylvanica |
58% sapwood | 20.0 | Good. Lighter, with less heat per cord. |
| Black ash Fraxinus nigra |
95% heartwood | About 19.6 or less (our estimate) | Fair. The wettest ash, with the longest drying time. |
Most of the ash we get is white and green. Their bark looks nearly identical, so it is hard to tell which one you are burning.
Black ash grows mostly in northern Wisconsin and only shows up in a load now and then. Its bark is easier to pick out.
Yes, it is the best of the ashes. Fresh white ash holds less water than fresh oak, maple, hickory, birch, or cherry, and it nearly matches red oak for heat.
Yes, with less heat. Green ash starts wetter than white ash and dries down lighter, about 2,880 pounds per air-dried cord versus 3,472.
Less weight means less fuel: about 20 million BTUs per cord instead of 24.
It is fair firewood, but slow to get ready. Black ash weighs about 34 pounds per cubic foot or less when dry, versus about 42 for white ash, according to Purdue Extension.
We found no extension table with black ash heat, so we estimated it from density: 34 ÷ 42 × 24.2 puts it at about 19.6 million BTUs per cord at most. It also starts the wettest, so it needs the longest drying time.
Mountain ash is not a true ash. It is a Sorbus, a shrub or small tree in the rose family, and the USDA Forest Service describes its wood as light, soft, and weak.
It burns, but it is not worth seeking out. Emerald ash borer does not attack it either.
It will burn, but not well.
Ash has a reputation as the one hardwood you can cut and burn the same day, and there is a real reason for it.
The USDA Wood Handbook puts fresh white ash at about 45% moisture, compared with 80% for red oak heartwood and 65 to 72% for sugar maple.
But 45% is still three times wetter than the 15% we dry our firewood down to. Wet wood spends its energy boiling off water, so you get hissing, more smoke, weaker heat, faster creosote buildup, and cloudy glass on a modern stove. The saying falls apart completely with black ash, which can hold nearly as much water as wood fiber when it is cut.
Pin meters lose accuracy once wood is wetter than about 30%, so fresh wood often reads lower than its true moisture. Use them to compare pieces, not as exact numbers. Our guide on how to use a firewood moisture meter covers the basics.
An old English firewood poem claims ash burns well whether it is wet or dry. Dry ash earns the praise. Wet ash just burns better than other wet wood.
Split and stacked, live-cut ash takes about 6 to 9 months to season in an Upper Midwest climate. Standing dead ash can be ready in 4 to 8 months.
Split it by early spring and it should be ready for the same winter. Ash is one of the few common hardwoods where that works.
It dries fast because it starts with less water, not because it is a light wood. White ash is nearly as dense as red oak. It just starts much closer to the finish line.
That head start makes ash a favorite with sellers who air-dry instead of kiln-drying. But "seasoned" on a label is not a promise.
Split a piece and meter the fresh inside face before you pay. Our guide to what seasoned firewood really means shows what to look for.
In our kilns, ash usually comes out in about a day, while red oak takes closer to two. Live-cut ash takes a few hours longer, and every load depends on how wet it arrives.
For other species, see our guide to how long firewood takes to season.
Yes, as long as the wood is still sound. Emerald ash borer has killed most of the ash in the southern half of Wisconsin, and standing dead ash starts drying before anyone cuts it.
You can see it on a truck scale. Our log semis run to a 98,000-pound gross limit, so the number of cords that fit shows how much water the wood is carrying:
Same truck, same weight limit. The difference is mostly water. For per-cord weights by species, see our guide to what a cord of firewood weighs.
Dead ash does not stay good forever. Ash has no natural decay resistance, and once it has been dead a long time it loses density and breaks down faster than most hardwoods. Punky, crumbly ash burns fast and gives little heat.
Our logging partners know not to bring us punky wood. When long-dead ash does come in, we dry it for a shorter time, check pieces with a meter, and burn test them to see how they actually perform.
If a tree service wants to haul away your ash, check the base and center of the cut logs for soft, punky wood first. Sound ash is worth keeping.
Long-dead ash can also be brittle and dangerous to cut down, so leave standing dead trees near your house or power lines to a certified arborist.
Oak is better for long, overnight heat. Ash is better for starting fires, daytime heat, and the in-between months of fall and spring.
Ash also gets ready to burn much sooner. Most wood burners do best with some of each.
| Wood | Heat per Cord (million BTU) | Air Seasoning (split) | Best Use |
|---|---|---|---|
| White ash | 24.2 | 6–9 months | Starting fires, daytime heat, shoulder season |
| Red oak | 24.6 | 18 months typical | Overnight burns, long-lasting coals |
| White oak | 29.1 | 18–24+ months | The coldest nights |
| Hard maple | 25.5 | 12–18 months | Steady all-day heat |
| Birch | 20.8 | 8–12 months | Quick, bright fires |
| Cherry | 20.4 | 6–12 months | Aroma and ambiance |
For a closer look at each of these woods, see our guides to oak firewood, maple, birch, and cherry.
Ash has a few real downsides, none of them deal breakers:
Emerald ash borer is why so much dead ash is out there, and why you need to be careful moving it. It was first found in Wisconsin in 2008 in Ozaukee County and was confirmed in all 72 counties in 2024, according to the Wisconsin DNR. It mostly spreads to new areas by riding along in firewood.
Cutting a tree down does not get rid of the beetles inside it. In a USDA Forest Service study, adult beetles came out the summer after the logs were cut, no matter when they were cut.
Heat is what stops them. The heat treatment standard many states use for emerald ash borer in firewood is 140°F at the core for 60 minutes, according to the National Plant Board.
Our bundles are heat treated to USDA standard T314 (160°F at the core for 75 minutes), and we are certified under USDA-APHIS compliance agreement SM-WI-1233-HT and Wisconsin DATCP HT# 2019086. We do not dry wood just to pass a certification, though. We dry it to burn right.
If you cut your own ash, burn it near where the tree came down. If you buy it, buy local or buy heat treated. Our firewood transport guide covers the rules.
Ash is the most common wood through our kilns. It makes up just over half of our mixed hardwood blend through the year, and a lot of it goes into our bundles. Much of it comes from:
We dry it at a 265°F chamber temperature until it reaches 15% moisture, which usually takes about a day. A cord of our kiln-dried, ash-based mixed hardwood weighs about 3,000 to 3,500 pounds.
Several of the wood-fired pizza restaurants we supply burn that same mixed hardwood, because a pizza oven needs clean, steady heat, not smoke flavor.
Learn more about the process in our guide to kiln-dried firewood, or see our kiln-dried mixed hardwood firewood.
Yes. Ash trees (genus Fraxinus) are deciduous hardwoods. White ash is nearly as dense as red oak, so it puts out similar heat per cord. Green and black ash are lighter.
Yes. Dry ash lights easily, burns hot, and makes little smoke. In a wood stove, add denser wood like oak for overnight burns, since ash burns down faster.
No more than any other dry hardwood. Creosote builds up mainly from burning wet wood and running slow, smoky fires. Dry ash burns clean. Wet ash, like any wet wood, will add to creosote.
Cracked ends, lighter weight, and a sharp clunk when two pieces knock together are good hints. To be sure, split a piece and check the fresh inside face with a moisture meter. Air-seasoned firewood should read 20% or less there.
Yes, when you need heat rather than smoke flavor. Ash has very little smell or flavor, which makes it a solid pizza oven fuel. For smoking meat, hickory or cherry are a better fit. See our cooking firewood guide.
