Farewell to Autumn- Part Two

By Martin L. Klein

It’s mid-November and I’m looking forward to Thanksgiving. Times are tough for many, and I am no exception, but when we feel down and maybe a bit fearful of our circumstances, there is one thing we can always do to put things in perspective. Start counting.

Count the people in your life who love you, count the material things you do have that others may not. Be thankful. To be sure, oftentimes God gives me what I need, not what I want. And that’s probably a good thing. I wish you all a happy Thanksgiving with family, friends, and a warm fire to gather near.

The impending winter onslaught I alluded to in Part One has not fully materialized. It is, however colder than it was then, and we barely avoided a first snow here this past week. So farewell to you old Autumn. It certainly was a splendid one.

I’ve been cutting and stacking next year’s firewood logs while the weather allows. It is so nice to have it all cut and ready for splitting come early spring. It’s a shame that by the time it gets fully seasoned, a certain percentage of it will fall prey to a certain pest that most of you are probably familiar with- the powder post beetle. Or maybe you are more familiar with the results of this pest. Fine, flour-like dust throughout your seasoned wood-stack, and tiny holes bored into the wood. A very annoying situation to discover when it’s time to use or to sell the wood.

Each and every piece of firewood must be swept, clean, and beaten against a hard surface to remove the fine powder. But take heart, it isn’t the end of the world…or the wood, rather.

There are various types of wood-boring beetles, most of which affect dead wood. Standing dead hardwood trees are their usual fare. But, as a rule, any dead wood that is dry will attract wood-boring beetles. Apparently wood releases different chemicals according to its state of demise. The beetles are drawn to the wood by the scent of these chemicals, and, your supply of seasoned hardwood is no exception to this rule.

It is the scent of the driest wood that usually does the trick. The most common culprit is the powder post beetle. During the mid-summer months the adult beetles are drawn to dry hardwoods and quickly lay their eggs thereon. The eggs hatch, and the larvae immediately begin to bore into the wood where they will stay until warm weather arrives again. They are very efficient at expelling the digested wood as they tunnel in, usually stopping shy of the heartwood, which contains tannins they don’t prefer. You’ve probably seen the tiny holes visible on a piece of split hardwood and the piles of fine powder lying on each succeeding layer of stacked firewood. They also leave a system of tunnels caked with powder under loose bark. This is a sure sign that your infested wood is not only thoroughly dry, but probably was dry enough to burn last mid-summer or the beetles would not have chosen it to make their happy home in. I have noticed that it is usually my supply of split Hackberry and White Ash which tickle their fancy. This is because both of these hardwoods are of low moisture content to begin with when cut fresh, and they tend to dry rather quickly. Add a very dry summer to this equation, and you are now attracting adult wood-boring beetles to your firewood. My other hardwoods with a higher moisture content, such as Hard Maple, Elm, Cherry, or Oak are not so nearly affected, as by the time they are dry enough to attract the beetles, Autumn is well underway and temperatures are too low for this insect’s activities.

So, what can you do to stop these junior sawmills from turning your hard work into Pillsbury flour? Very frankly, damage control is probably going to be easier than any measures you would need to take to actually stop them. These insects are a natural part of the decaying process of the forest, helping return dead trees to the soil from whence they came. So it helps a bit to know that they were created for a very useful purpose, at least.

Now let’s look at some measures we can take to reduce the beetle-attractive nature of your firewood. One thing you do not want to do (even if you want to) is to treat your firewood with any type of chemical pesticide. This creates a very likely health hazard when the wood is eventually burned in the stove or fireplace. And besides, you would be adding more noxious chemicals to an environment already rife with chemicals enough. Not a good idea. That said, I would recommend that fresh cut firewood from healthy trees be seasoned in an area protected by screening, such as an outdoor screened-in porch or screen house if at all possible. This is the best method of preventing infestation by adult beetles. But if you stock hardwood in above average amounts such as I do, this would not be practical. In the case of seasoning large amounts of firewood in unprotected stacks, it would be a good idea to pay more particular attention to the woods with the lowest natural moisture content such as those I referred to, and also any un-infested dry deadwood acquired which will sit outdoors during the summer months. Try using tarps to cover the driest woods during mid-summer. This will prevent a fair amount of the access the adult beetles would normally have to the wood. And when the average temperature drops to 50 or below in the autumn months, beetle activity ceases and you can un-tarp at will. Also, do a thorough check of any trees you intend to cut up for firewood. If you notice signs of wood-boring activity such as tiny holes in the bark and exposed wood, or fine dust in spots on the trunk or directly at the base of the tree, it may be best to leave it be.

If you’ve seasoned your wood, winter is upon you, and you discover that the beasts have done their dirty work, don’t panic. The wood, in most cases, is still perfectly usable. You will not, however, wish to store any of it indoors in the warm environment of your house. Although softwoods, such as pines, and any wood with a finished surface is not likely to be a wood-boring beetle target, you still don’t want to encourage beetles to emerge from your wood before it hits the fire. Bring in only that which you intend to burn the same day. And be sure to burn all of the infested wood before spring arrives. Don’t leave any over for next winter.

So, even though the subject of powder post beetles is an exhaustive one, I won’t exhaust you any further with it. There are many types of these insects and I am no expert on the subject by any means. But I hope that the information I do have will be helpful to you if you are unfamiliar with the problem and considered your firewood to be a total loss upon its discovery. I had intended to gab further and tell you a nifty way to fight that dry winter air usually made even dryer by heating with wood, but the beetles ate up all my time. I promise to address it in my next letter, although it isn’t really worthy of any great anticipation. So until next time, have a warm Thanksgiving, and… Happy Wood-burning!

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