Cottonwood (Populus section aigeiros) is part of the poplar (Populus) family and is native to America. As such, cottonwood grows all over the US, taking a particular liking to moisture soils. You will often find them near lakes and rivers.
Their love for moist soils makes cottonwood very effective flood and erosion barriers. But are they worth using for firewood?
Cottonwood is a fair-burning firewood overall but does not generate a lot of heat compared to premium firewood like oak or locust. It is clean burning but does not produce more heat than 17.1 Million BTUs per cord.
What Are The Varieties Of Cottonwood
There are a few subspecies of cottonwood, but there are two that stand out as firewood choices:
Black cottonwood – One of the largest hardwoods to grow in North America, black cottonwood is actually native to Europe and Asia but is now extremely common in North America.
Eastern cottonwood (Populus deltoides)– Unlike its name would suggest, eastern cottonwood is not limited to the east of the US but also crows in central and southwest North America.
Cottonwood is often grouped with other poplar species as firewood, but it is worth noticing as its own separate species with its own variations. Its wood variations do have slightly different burning qualities to poplar.
What Are The Physical Characteristics Of Cottonwood
| Name | Cottonwood |
| Heat per cord (Million BTUs) | 14.6 – 17.1 |
| Weight dry (lbs per cord) | 2122 – 2475 |
| Weight green (lbs per cord) | 3910 – 4165 |
| Seasoning time | 6 – 12 months |
| Resin / Sap content | Little |
| Splitting Difficulty | Easy |
| Smoke | Moderate |
| Smell | Light |
| Coal Production | Moderate |
| Creosote Build-up | Moderate |
Does its Wood Split Easily?
Cottonwood is very high in moisture as it prefers wet soils. As such, when still fresh and green, it can be difficult to split as its fibers remain stuck together. This doesn’t causally make its wood harder but stringier, making it hard to split cleanly.
The stringy quality of the cottonwood when wet also means that the wood will absorb your ax rather than split apart like it is supposed to.
It is better to season cottonwood for half of its seasoning time (6 months) before splitting, creating a firmer but easier wood to split.
Aside from its excess moisture, cottonwood should be pretty clean to split as most of its sap is stored inside the leaves.
How Much Sap Does It Have?
When it comes to sap, cottonwood is a unique case.
It does have a lot of sap, but it is not produced and stored in its wood, like in pine trees. Instead, the sap prefers to gather in the tree leaf buds, creating sticky leaves and branches.
If you are chopping your own cottonwood, aim for the trunk and thicker branches, avoiding areas with a lot of buds or leaves. That way you won’t have to deal with excess sap and the burning issues that come with sappy wood.
How Does The Wood Smell?
Unseasoned cottonwood is known to have a very unpleasant smell, especially while burning. This is mostly true of all unseasoned firewood but is especially obvious with cottonwood.
Once seasoned, cottonwood smells a whole lot better. It is quite a light scent, often unrecognizable. But it is still pleasant.
Heat Output And Efficiency Of Cottonwood
Cottonwood is a hardwood but is a very low BTU producing hardwood. In fact, some species of cottonwood produce a lower BTU than many softwoods.
It is eastern cottonwood that generates the most heat even though it is one of the softer cottonwoods, with a BTU of 17.1, but black cottonwood performs considerably weaker, offering a 14.6 BTU.
Fire Characteristics Of Cottonwood
Part of the reason that cottonwood is not an effective source of heat is that it is a lot less dense than other hardwoods. A cottonwood fire will burn longer than cedar or other softwoods but will burn up very quickly compared to most hardwoods.
During its burning time, it will not produce a lot of heat so it will feel as though it burns up a lot quicker than it does.
That being said, cottonwood creates moderately decent coals, which keep it burning for as long as it does. But the amount of ash it creates far outweighs its coal production.
Being such moist wood, cottonwood will need to be seasoned thoroughly before being burnt. Once it is dry, it is a clean-burning wood. The smoke it creates is very light and not at all suffocating.
Burning at such a low BTU means that the organic matter within the wood (aka the sap, moisture, etc) will not be able to properly burn away as the fire is not hot enough.
This leaves more particles to rise up with the excess smoke created by cottonwood and cling to your chimney and flutes.
For this reason, cottonwood does create a moderate build-up of creosote despite the smoke itself being fairly clean.
Is It Okay To Burn Cottonwood In A Fireplace?
You can burn cottonwood in your fireplace with relative ease, though you will not get a very hot fire from it.
When burning cottonwood in a fireplace, it is important to keep on top of its ash production. An ashy fireplace will make it very hard to ignite another fire, so make sure to clean up after you have burnt cottonwood.
To make burning cottonwood in your fireplace safer, mix it in with some better burning hardwood like oak.
Doing so will help to create a more efficient fire and produce hotter flames that will burn away organic matter better. This will reduce the amount of creosote build-up when burning cottonwood.
How Expensive Is Cottonwood Firewood?
Cottonwood can be fairly inexpensive considering how common it is in the US and the rate at which it grows – very fast, up to 1 meter a year.
How Long To Season Cottonwood
Cottonwood requires a little bit more effort when it comes to seasoning. Its high moisture levels mean you will need to season the wood for a few months, split it and then dry it again.
By splitting the wood halfway through the seasoning process, you will ensure that the whole of the center of the wood has a better chance of drying out quicker.
When following this seasoning process, you can expect to have ready-to-burn cottonwood in 6 – 12 months.
Pros And Cons of Cottonwood Wood
Pros
- Clean burning
- Short seasoning time
- Decent coaling
Cons:
- Time consuming processing methods
How Does Cottonwood Compare To Other Firewood?
Compared to other poplar species, cottonwood burns very well. It produces better coals and can burn for longer though it does tend to produce more smoke, even if this smoke is generally clean.
However, cottonwood is one of the lowest burning hardwoods. So much so that its highest BTU is 50% of most oak varieties.
Cottonwood also tends to take more effort to season.
Frequently Asked Questions:
Can Fireplace Ash Be Reused?
Ash will hinder another fire’s ability to burn, but it can be used as fertilizer for most plants. It can also help to melt ice in driveways or on paths.
How To Tell Is A Wood Is Seasoned Properly?
You can sometimes tell by the change of color or texture of wood if it has properly seasoned. However, it is always best to check with a moisture meter.
Conclusion
Cottonwood is fair-burning firewood overall, but it is one of the weakest hardwoods you could burn with a BTU only able to reach heights of 17.1.
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