Firewood can be an excellent heat source during winter, and of course does not add any new carbon dioxide to the atmosphere (all carbon in wood was pulled from the air during the tree's growth). However, it is very, very important that any firewood you use be grown very close to the area you plan to use it. Transporting firewood across any distance can allow invasive and destructive insects and other pests to invade new trees, threatening whole forests. The number of invasive insects alone -Asian Longhorn Beetles and Emerald Ash Borer to name only two in the author's area- is long and keeps increasing. Firewood must be grown close to the site of its use.
However, many areas do not have a great deal of naturally occurring trees, and many of those alive in such areas are too valuable to be cut for firewood. What can be done in this situation?
The answer is simple - plant fast growing trees with the Groasis Waterboxx, stagger when you harvest the trees, and use these trees for firewood. What trees are both fast growing and suitable for firewood? The five we recommend at Dew Harvest are the poplar (Populus species), the silver maple (Acer saccharinum), the Red Oak (Quercus rubra), the thornless Honeylocust (Gleditsia triacanthos inermis) and the Hackberry (Celtis occidentalis).
First, the poplar is extremely fast growing, with some hybrids growing up to 8 feet per year. The poplar grows straight, with relatively short branches, allowing these trees to be packed densely. Huge tree farms 25,000 acres large have been planted with nothing but hybrid poplars.
Because the poplar is so fast growing, it is not very dense and doesn't store as much energy per volume of wood (around 16 million BTU per cord) as other hardwoods. As a comparison, natural gas currently costs $9.50 per million BTUs, while propane is $33.00 per million BTUs, and electricity is around $24.91 per million BTUs) Because of this lower energy density, you can use poplar for kindling or starting a fire, and then chose another tree for its longer burning properties overnight. For this, we recommend silver maple.
Silver maple is also very fast growing (the author has personally seen silver maple grow six feet in a year between a shed and fence with limited sunlight), but doesn't have quite as compact a form as the poplar. Silver maple has branches that can spread out up to 40 feet, and will take slightly longer to reach maturity. Silver maple, however, contains about 19 million BTU per cord and doesn't spark as much as poplar.
A third option for much of the country is red oak (Quercus rubra). This oak is almost as fast growing as silver maple but gives 21.7 million BTU per cord. Red oak grows in zones 3-8 (all but the most southern part of the country) and have some drought tolerance, improved when planted with the Waterboxx. This tree can easily grow two feet a year even without the Waterboxx, and more with it.
A very drought resistant tree with a high energy density is the Honey Locust (Gleditsia triacanthos inermis). This tree has 25.8 million BTUs per cord, light smoke, and is easy to split. It is so drought resistant that it is easily grown in most parts of the country if planted with a Groasis Waterboxx. Buy the Thornless Honeylocust.
Slightly less drought resistant but a very tough tree is the Hackberry (Celtis occidentalis). This tree grows in zones 3-9, withstands some drought, as well as strong winds and pollution. It has 21 million BTUs per cord of firewood, doesn't spark, doesn't smoke, and is easy to split, making it and ideal firewood tree. Buy the Hackberry here.
When growing these or any trees for firewood, you must obtain the young trees for a good initial price and ensure that they survive to adulthood. Poplars are not generally available from garden centers; buying maples from these stores will be both expensive and futile since their roots are so malformed that they will grow very slowly. Because of these issues, we recommend buying bare root trees from the Arbor Day Foundation. With a ten dollar membership, bare root trees cost around five dollars each, and can be ordered in large quantities for significantly cheaper than that.
However, if these trees are planted and not cared for through a dry summer (another recent phenomenon in most of the country), they will be a wasted investment. That is why the Groasis Waterboxx is used. If you plant young bare root trees using the Waterboxx, you increase their chance of survival greatly, and increase their rate of growth. The Waterboxx funnels dew and rainwater to the roots of the growing tree, ensuring the roots reach deeper for water and allowing them to survive future droughts. In a Sahara planting trial, trees planted with the Groasis Waterboxx that received water only at planting had an 88% survival rate, versus only 11% survival for the trees watered weekly. The Waterboxx is reusable for up to ten years, allowing you to plant trees year after year and harvest wood indefinitely. Finally, the Groasis Waterboxx allows you to establish trees in areas that may be too dry for trees to start growing otherwise, harnessing the sunlight of summer for heat in winter. The Groasis Waterboxx can be purchased from Dew Harvest.
|The Groasis Waterboxx with an oak grown from seed.|
Depending on your firewood needs, a set of five to ten Waterboxxes and as many young poplars or maples planted each year will likely keep you warm indefinitely, once the trees have had time to get established (three to five years). Since the Waterboxx can be reused, only the trees need to be purchased each year, not the Waterboxx. This system will almost certainly be cheaper than electric or propane heating and will of course be better for the environment as no net carbon is released.
Buy Hybrid Poplar from Arbor Day
Buy Silver Maple from Arbor Day
Buy Red Oak from Arbor Day
The Groasis Waterboxx can be purchased for around fifty dollars from Dew Harvest, with discounts on orders of five or more. The Waterboxx can be used to establish new trees for any purpose (such as landscaping or to prevent soil erosion), not just firewood growth.
You can see all our blog posts about planting trees with the Waterboxx here. We would love to hear your comments below - to leave one, please click on "Comments".
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