Cottonwood is moderately good for firewood because it is a hard wood that splits easily when seasoned properly, burns relatively clean and produces a fair amount of heat. They are difficult to split when green and if not seasoned properly give off a very unpleasant aroma.
Keep reading to learn more about Cottonwood and why you might want to choose it for firewood.
Common Characteristics of Cottonwood Trees
Cottonwood, also known as the poplar, it is named for its cotton-like seeds. When the seeds are in the air it seems like it is snowing.
Cottonwoods are used as shade trees and grow naturally throughout the United States. They have broad, white trunks, bright green leaves in the summer and bright yellow leaves in the fall.
The trees grow in locations with full sun and lots of moisture. You will often see them growing along lakes and rivers as well as marshy areas.
They grow very fast! They are the fastest growing trees in North America, adding 6 feet or more in height every year.
Common varieties of Cottonwood trees in the United States
The Eastern Cottonwood is one of the largest North American hardwood trees. The leaves are triangular shaped and have coarsely toothed edges. It is found throughout the eastern United States and southern Canada.
The Fremont’s Cottonwood is native to the southwestern United States and western Mexico. Its leaves differ only slightly in that they have larger serrations than the Eastern Cottonwood does.
Working with Cottonwood Firewood
What does Cottonwood smell like?
All types of wood can be used as firewood but some are better than others. Besides investigating how much heat is produced you also need to consider the aroma of the wood.
Most woods produce fruity, nutty, or piney fragrances. However, Cottonwood is often given a bad rap for smelling like cat pee, but when seasoned properly it doesn’t give off this revolting smell.
Is Cottonwood sap messy?
When cutting Cottonwood it is pretty clean to work with unlike Pine which has a lot of pitch and will gum up your chainsaw.
Cottonwood trees make really good shade trees, but they also produce an abundant amount of sap that irritates people who park their cars under them. The sap oozes from a Cottonwoods leaf bud and can make a mess of your car or truck. This shouldn’t bother you much since you will be dealing primarily with the trunk of the tree and not the branches.
Recommended ways to remove the sticky mess is with WD-40, finger nail polish, baking soda paste, or mayonnaise.
Cottonwood sap is used in folk medicines and massage oils. Some Native American tribes have been said to used their sap as a sweetener in teas, pudding and syrups.
How hard is Cottonwood to split?
There are many mixed feelings in regards to Cottonwood as firewood. While many people consider it a very difficult firewood to split, there are others who have no issues with it.
The reason there are mixed opinions is because some are splitting it while it is green and some have seasoned their Cottonwood first.
When green, Cottonwood is very wet, stringy and heavy, which makes it hard to move and difficult to split. The wood just seems to absorb a maul or splitting axe rather than splitting apart.
When seasoned 6 months, or even 1-2 years, splitting becomes much easier. To season it, stack it off the ground and cover the top portion of the stack if possible. When the wood is dry it splits pretty easy and makes good kindling.
If you are in a hurry to split it, stack your freshly cut cottonwood rounds off the ground for 1-2 weeks. Then go ahead and start splitting and stacking. This will give you a little bit of dry time and allow for easier splitting.
How long does Cottonwood take to season?
Cottonwood does not burn well when green. It will not light quickly and will produce a lot of smoke. You should let your cottonwood firewood season at least 3-6 months after being split. If you leave it in rounds, let it season for 1-2 years.
In general, to get the most energy out of your firewood, the wood should be well seasoned. Seasoned firewood is described as having 20% moisture content. A good rule of thumb is to cut firewood this year so you can use it next year.
Burning green wood decreases the amount of heat generated by it. As the green wood burns, the energy created from the fire is used to evaporate the moisture resulting in wasted heat.
Buy an inexpensive easy to use moisture meter like this one, to ensure your split wood is ready for the fire.
Does Cottonwood burn clean?
Cottonwood firewood will burn clean when it is seasoned properly. When green it is difficult to burn and will smolder and make smoke because it holds a lot of water.
Heat Output and Efficiency of Cottonwood
Cottonwood firewood has a fairly low BTU. It is rated between 15.8-16.8 million BTUs per cord.
On average a cord of Cottonwood is equal approximately to the following common heat sources:
- 15,700 cubic feet of natural gas.
- 178 gallons of propane.
- 118 gallons of heating oil.
- 4,777 kilowatt hours of electricity.
BTU stands for British Thermal Unit. One BTU the amount of energy required to heat one pound of liquid water by one degree Fahrenheit.
A cord of firewood is equal to 128 cubic feet of wood. Typically firewood is cut into 16 inch lengths and is tightly stacked in three rows, 4 feet high and 8 feet long, totaling 128 cubic feet.
How does Cottonwood compare to other types of firewood?
Cottowood falls somewhere towards the bottom in terms of BTUs per cord. At the high end would be Eucalyptus at 34.5 million BTUs per cord and Osage-Orange at 32.9 million. On the low end you have Ohio Buckeye at 12.1 million BTUs per cord and Linden Basswood burning at 13.8 million. Cottonwood has a BTU rating of 15.8-16.8.
Fire quality, amount of smoke and creosote.
Cottonwood is safe to burn in a fireplace if it is seasoned properly. Otherwise you may end up with just a lot of smoke. Oftentimes people will mix Cottonwood with a soft wood like Pine when burning in a wood stove or fireplace because Cottonwood all on its own doesn’t do the best job at heating your house.
Green wood tends to smoke and smolder creating the possibility for creosote to form in the chimney. Creosote is nothing more than a condensation of small, unburned particles contained in the smoke that coats the chimney surface as it exits. The creosote will stick to the sides of the chimney and dry. Then it can can ignite, causing a chimney fire.
All wood creates creosote. When Cottonwood is dry it will ignite fast and produce heat quickly, but it doesn’t last long and will leave a lot of ash.
The Pros and Cons of Burning Cottonwood as Firewood
Pros
- Very common tree in the United States.
- Splits and lights very easily when dry.
- Clean to handle.
Cons
- Very difficult to split when green.
- When not seasoned properly gives off an unpleasant aroma. Some say it smells like cat pee.
- Takes longer to season properly than most hardwoods.
- Burns quickly.
Other Common Uses
Native Americans used Cottonwood trunks for dugout canoes. The bark was used for food for their horses as well as in medicinal tea.
Cottonwood trees tend to warp and shrink, and the wood doesn’t have an attractive grain, so the wood is often used to make pallets, crates and boxes.
There are many different firewood species to choose from. However, not all of the options will be available to you since some trees only grow in certain parts of the country. In my opinion, Cottonwood can be a great choice when given the time to season properly.
Tell me what your favorite type of firewood is in the comments below.
I have spent the last four hours researching the subject of cottonwood as firewood – (Actually, I was looking for info about using the ash, to little avail.) I’ve seen a lot of misinformation, mostly based on, IMHO, Ignorance and “pappy” tales.
I live on a small ranch in a remote corner of Wyoming. A bifurcated creek forms an island on which grows and abundance of Cottonwood (it actually becomes a bit of a nuisance), and where the ranch house, barns, corrals, orchard and garden are located.
We get high winds seasonally (gusts 140 MPH have been recorded) and weak branches and old trees topple to the ground seasonally. It’s a constant battle to keep the litter cleaned up. Some areas of the ranch remain uncleared for years at a time, meaning lots of well seasoned firewood, when we get around to harvesting it.
The ranch house is heated almost exclusively with Cottonwood. I have burned this wood in all it’s stages, from fresh cut to “dead on the ground for years” (due to the twist and warp, only part of a fallen tree is in actual contact with the ground). Last fall we upgraded the furnace to a Quadra-Fire which has greatly improved the economy of the burn.
My experience is, like others, well seasoned cottonwood is just fine for burning. REALLY well seasoned cottonwood logs do NOT pop and spark – at least no so you’d notice in a furnace that is properly maintained. However, the twigs and fronds can pop and spark like green pine.
As it is necessary to clean up wind-tossed branches, we have a LOT of green firewood that gets burned without any serious seasoning. “Green” cottonwood (maybe a week or so ‘off the tree’) will still burn if placed in a hot enough environment, like a furnace with a goodly bed of coals. Of course, THEN you get popping and sparking – As mentioned elsewhere, a lot of the heat is lost to boiling off the water. However, in our Quadra-Fire, the smoke is burned as it goes through the “after burner” – only on a cold start do I see smoke out of the chimney – otherwise little to no smoke, and all you see at the chimney top is the shimmer of the heat waves.
I hope this helps answer some questions –
Thanks for your comment and explanations. I hope that your details will be of benefit to everyone. It sounds like you have an abundant about of Cottonwood to burn and that your new furnace is working great for you!
Surfed and surfed and surfed – cannot for the life of me find comments about cottonwood ASH — My step son (50-ish) says not to use it in the garden as it contains toxic elements that other wood ash lacks. I’m skeptical – sounds like “pappy” tales. Is there any scientific basis to this tale?
I don’t have any experience with that. Since it is a hardwood it will have more nutrients than other softwood ashes though.
Lacking any scientific information, have decided to run an experiment – going to select an area of the garden that is down-hill and down wind and plow in a massive amount of Cottonwood Ash and let the area lie fallow for several months to see what pops up.
We cut and sell cottonwood every winter. Selling around 15-20 cords every winter. As long as it’s split and seasoned people we sell it to really enjoy it and have no problems with it.
That’s great! Glad so many people find it useful. Would you mind sharing how much per cord you sell it for?
Update on the Cottonwood- The green cottonwood smolders and produces strong, malodorous smoke. Then end result was very ashy. I feared the cottonwood was junk wood. I stacked several remaining rounds in full sun for the entire summer. In late September, we split the rounds (half the weight as before) with absolute ease. Again, the wood was bug free and clean. I stacked it covered and returned to it a week ago for burning in my new EPA indoor stove. Unlike the greenish logs, the cottonwood lost the bad odor, replaced by a sweet sagelike scent. It burns well and I compare it to doug fir, but without the messy sap and bark. The ashes are minimal. Again with my moisture meter, now it’s at about 12-14%. Been burning it now since our first early cold (27degrees) and I am SUPER happy with it. I prefer oak or ash wood for BTU, but this free cottonwood is great. The good: lightweight, no sap, splits very easy, minimal ash, no messy bark. The bad: lower BTU’s and some might find the sweet smell unpleasing. We like it. Conclusion: Dry cottonwood is worth it’s weight.
That’s great info! Thanks for sharing with us.
Northern Oregon here. We just cut a healthy 105 foot Cottonwood from our property because it’s roots were damaging our foundation. The wood is very, very clean and completely bug-free. The rounds are super heavy. With a moisture meter, the green wood reads 49% consistently. To my suprise, the rounds split by hand-axe with absolute ease. The grain is very straight. I’ll be stacking about 6 cords yield from the tree for a year before burning.
Wow! That is awesome! Thanks for sharing this information with us. So glad you found a great source of wood on your own property. 6 cords, wow!
Hi PNW Pete, sounds like a great tree you got there! Thanks for sharing! 🙂