Though it is often overlooked due to being a softwood, hemlock (Tsuga) is worth considering when choosing your firewood. Hemlock (derived from the Pinaceae family), is very common in North America, growing in acidic and moist soils and providing shade to other trees.
If you have hemlock growing in your back garden, is it worth turning into firewood?
Some varieties of hemlock make better firewood than others. Mountain hemlock can generate a BTU of 20.1 million per cord and will last up to 10 hours at a steady heat in your fireplace. It is also a wood that creates a cozy ambiance between its pleasant smell and soft crackles. Because of its popping nature, it is best used in a closed fireplace.
What Are The Varieties Of Hemlock Wood?
There are 3 varieties of hemlock that make decent firewood to varying degrees: east hemlock, western hemlock, and mountain hemlock.
They are all low-density woods meaning that they burn up quickly. But while burning, they all release different BTUs.
What Are The Physical Characteristics Of Hemlock Wood?
| Name | Hemlock |
| Heat per cord (Million BTUs) | 17.1 – 20.1 |
| Weight dry (lbs per cord) | 2474 – 2917 |
| Weight green (lbs per cord) | 3495 – 4250 |
| Seasoning time | 7 – 12 months |
| Resin/ Sap Content | Medium |
| Splitting Difficulty | Easy |
| Smoke | Low |
| Smell | Nicely aromatic |
| Coal Production | Very poor |
| Cerocote Build-up | Low |
Is Hemlock Easy To Split?
Due to its smooth grain, hemlock is exceedingly easy to split. It has a low sap content so will not make a mess like pine but also is durable enough that it will not start rotting for a few years.
How Much Resin Content Does Hemlock Have?
Even though it is related to the extremely sappy pine tree, hemlock does not carry a lot of sap. In fact, it is considered a non-resinous species as the sap content is so low.
Of course, every tree has to produce some level of sap to deliver nutrients to various parts of the tree. So, cut hemlock during winter when the little sap it does produce travel to its roots, leaving a clean, mostly sap-free wood.
What Does Hemlock Smell Like?
When fresh, hemlock has a pleasant smell which is reflected in its burning aroma.
It is not as pleasant as Cedar, nor does it carry any spicy undertones like tulip poplar firewood. But it is a nice smell to have in your home and will help to create a cozy ambiance.
Moisture Levels Of Hemlock
Hemlock is a very water tolerant tree, preferring growing in moist and acidic environments over dry ones. It does not retain the water for moist soils for long and so has a generally low level of moisture when cut down.
Heat Output and Efficiency of Hemlock
It depends on which type of hemlock firewood you use as to how effective of a fire you can make.
Mountain hemlock is the best performing firewood of its species, capable of producing a BTU of 20.1 – on par with similar high-tier conifer firewood like douglas fir and eastern red cedar, and hardwoods like silver maple.
However, eastern and western hemlock does not burn as hot, with BTUs of 17.1 and 17.7. Though this is still a higher BTU than most fir species are capable of generating.
Read more on fir varieties as firewood in this post.
Regardless of their BTU capabilities, hemlock wood can generally last considerably longer than other softwoods like western red cedar.
Fire Characteristics Of Hemlock
Let’s look at the fire properties of hemlock to see whether it’s the correct firewood for your needs.
Creosote build-up
It is important to know how likely firewood is to create creosote and to what degree so that you know how often you need to clean your chimney.
Creosote is a tarry by-product of burning wood and clings to flute or chimneys like glue. It is extremely flammable and should not be left to build up.
Hemlock has both a low moisture and sap content even if freshly cut. As long you allow hemlock to season properly and reach a moisture content level of under 20%, it will produce very little creosote.
Amount Of Smoke
With little moisture to feed off after seasoning, hemlock produces little smoke.
Though every fireplace should have good ventilation, you would be able to burn hemlock on an open fire. Likewise, you could use hemlock to cook outdoors with and have very few smoking issues.
Does It Produce Coals?
While hemlock is capable of burning for longer than most conifers, it does not produce any coals to keep it burning for an extended time. Instead, it burns up entirely, leaving an obscene amount of ash behind.
Usually, wood needs to produce coals to keep a fire hot and burning, but hemlock burns slow enough that it does not need coals to maintain a constant heat for a longer time. Much like chestnut firewood.
Is It Okay To Burn Hemlock In A Fireplace?
Hemlock can be fairly hazardous firewood to burn in a fireplace due to the number of sparks that it produces. A simple fire screen should solve this problem if you are burning it in an open fireplace, whereas the safest way would be to burn it in a log burner.
It is also a pain to clean out after use due to the amount of ash that it produces, but it does make a good backup option during warmer winter days.
With all that in mind, hemlock is an ambient burn and can have your home feeling warm and cozy in no time. It also makes both good kindling and longer-lasting soft firewood.
How Long To Season Hemlock Wood?
One of the quickest drying firewood out there, hemlock only takes 7 – 12 months to season depending on when in the time of the year you cut it.
It only takes 4 – 6 months in ideal conditions to reach an acceptable burning state but to get the highest BTU you can get out of it, make sure to leave hemlock to season for at least 7 months if not longer.
Other softwoods like cedar take almost twice as long as hemlock to season and reaches a lower BTU than mountain hemlock. So, 7 – 12 months isn’t really that long to wait.
Is Hemlock Firewood Expensive?
Hemlock is not expensive firewood at all, especially when bough green, or in other words, unseasoned. According to Reedsfirewood, you can expect to pay 220USD for a cord of green hemlock.
Pros And Cons Of Using Hemlock as Firewood
Every firewood has its pros and cons, and so does hemlock.
Pros:
- Very fast drying
- Minimal smoke
- Moderate BTU
- Ignites easily
Cons:
- Moderate sparks
- Mild smell which you may or may not like
How Does Hemlock Compare To Other Firewood?
Compared to other softwoods, hemlock performs considerably well. Some of its varieties can reach just as high a BTU as some hardwoods. And even though it doesn’t produce as many coals as oak, it can burn through the night.
Although, sturdy hardwoods such as maple, oak, and beech are always going to provide a hotter flame for a longer amount of time.
During the cold months of winter, you want to rely on hemlock purely for kindling rather than as a heating source.
Frequently Asked Questions:
Is Hemlock Toxic To Burn?
Unlike the poisonous plant of the same name, hemlock wood is not toxic.
Can I Burn Unseasoned Firewood?
Simply put, the better your firewood has been seasoned, the better it will burn.
More time for your wood to dry will lower the quantity of smoke created when it is burned, allowing the fire to burn longer.
Conclusion
Hemlock is efficient soft firewood – especially mountain hemlock. You can achieve a moderately heated fire of 20.1 BTUs that will last up to 10 hours. But it does tend to spark, so make sure you have the right safety measure in place.
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I am the guy behind Theyardable.com. I grew up on a homestead and I am here to share the knowledge I have and things I learn while living in the countryside.
