Logging Northern Red Pine in Winter vs. Summer Moisture Content?

[Dad2FourWI]

While drinking hot coffee and sharpening chains for our saws, we started to debate over how long we have to cut down mature 75 year old northern Red Pines to keep the moisture content down as much as possible.

An old timer, that I respect very much, said that we should stop cutting by April 1st....

We are in central Wisconsin and we are trying to reduce the amount of moisture, and some feel that the trees are at their lowest levels towards the end of the winter.... but "when is the end?"... is the real question!!!!

We are still trying to figure out how to optimize our solar kiln, so we try to harvest as many Red Pine as we can while their moisture content is low.

Any and all input is very much appreciated!!!
Thanks,
-Dad2FourWI

[beenthere]

Think it is an "old wives tale" that you are hearing. Very little difference in moisture content throughout the year. 

[fluidpowerpro]

Maybe it don't matter when the tree is cut down, but I could understand the benefit of milling them before April 1st because in heat and humidity of the summer it's much more likely to mold.

[barbender]

I've been a part of harvesting red pine at all times of the year, and honestly I don't see much difference in the amount of moisture in the logs. In the dead of winter, mature pine logs look like solid ice. They don't look like they could hold any more moisture than they already are. 

[Ianab]

I could understand the benefit of milling them before April 1st because in heat and humidity of the summer it's much more likely to mold.

This ^

The moisture content of the wood doesn't change much, but the weather affects the logs and fresh cut lumber. If it's cold enough you don't have to worry about fungus and bugs like in the Summer. So the old timers learnt they got better results in Winter. 

Here in NZ it's seldom cold enough to prevent fungus getting into pine, and the faster drying in Summer usually works better. But you can't let the logs sit around, need to get them sawed and dry ASAP in the warmer weather. 

So there is some good reasons for the traditional Winter logging (as well as frozen ground and roads). But it's not related to moisture in the trees, 

[SwampDonkey]

Up here with mills you face just the opposite concerning moisture, they want wood as fresh as they can get it. And the logger does to because he's paid by the green weight. Like beenthere alluded to, fresh cut off the stump at any time of the year has very little variance in moisture content. If the live cells of a standing tree are starved for water that ain't good either.

Too much coffee and talking with 'jacklegs'.

[Don P]

A cell embolizes and the capillary column from roots to leaves is broken. Unless these guys pump their trees back up in spring, those trees are dead.

A pine tree keeps its needles through the year, and it is photosynthsizing all year too, that slush is moving in its veins whenever it is not solid. In deciduous trees the mc can be highest in winter when there is little transpiration going on. These are minor compared to the bulk of moisture to be removed.

Prove it. Go for a walk watching SW faces of trees. A frost check happens on a subfreezing sunny day. The bark warms, sap flows, the needles, if it has them, and bark itself photosynthesizes (ever noticed green in the bark, clorophyll, making winter rations). The tree is working, sap thins and flows. And then a cloud passes over, the tree freezes and you hear a rifle shot sound in the woods, a frost check. That tree was full to pop its seams.

Pines are the hardest working tree in the woods in winter.

[Bruno of NH]

I saw lots of red pine
If I saw it in July , August , and September it molds right after getting on sticks.
Sawn any other time of year it's no problem. 

[moodnacreek]

They say in the fall after the first frost the sap in the needles goes back in the sap wood. I guess that is why pine compared to , say spruce, is so heavy in winter. The big problem with any true pine is blue stain that appears as soon as the wood warms unless the mc is low. Once the tree is severed from the roots it can no longer cool it self. If the log can be kept cool [cold weather or in water] it will warm and stain unless it can be sawn and stickered and dried some before the blue stain can grow.  I think pine logs weigh more before the new spring growth starts.

[Dad2FourWI]

Thank you everyone for the awesome feedback!!!

Your experience and knowledge are always very much appreciated!

[M.R.]

My understanding or research into the Blue Stain fungus is that it'll grow at 56F & above with enough moisture present. 

One could even experiment double ringing with a saw? 

The IPS's in the slash can also be a concern here in the PNW.

[barbender]

M.R., do you mean girdling by that? Red Pine will blue stain standing, and deteriorate quickly.

[Ianab]

My understanding or research into the Blue Stain fungus is that it'll grow at 56F & above with enough moisture present.

I don't think it's a hard cut off number, but that's probably a good rule of thumb. Around that temp the fungus would be very slow, and the wood has a chance to dry out before it grows. Closer to freezing it won't be growing at all.  Like I mentioned we can get Winter days over that temp, with 95% humidity, so the Winter logging isn't so great here (lots of mud).  Most of the commercial mills and loggers operate all year round, and Summer months are preferred. But the logs get sawed and into a kiln a quick as possible. Logs for export are usually debarked and sprayed with an anti-sapstain fungicide so they survive a boat ride through the tropics to India / China / Japan etc. 

[Sod saw]

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Dad2FourWI.    It seems to me that your question and concern is about the wood moisture content and loading it into the kiln.

Our kiln chambers can only hold so many board feet.  Therefore, once a kiln is full,  you have to stop cutting or stack the wood boards safely  until the full kiln can be emptied.  I can cut a full kiln load in a day or two.  So, I need to figure out what to do to preserve the newly cut wood until that full kiln can be emptied.

While waiting for the kiln to become available again my newly cut wood is drying some.  This allows me to load dryer boards into the empty kiln and actually shorten the time needed for them to be inside the kiln.  

The moisture content of the logs is important as the logs are stored but as soon as they are cut into boards, they start to dry and are becoming ready to load into the kiln.

As others here have said, the kiln drying / heat treating cycle is the slow bottleneck of this process.  Take advantage of this opportunity to pre dry (air dry). your kiln loads.   You might just get another load or two thru your kiln each year.


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[Dad2FourWI]

Thanks Sod saw,

yes.... all about moisture..... I was hopeful that by cutting down the trees during the height of winter, we might have the logs at a lower moisture content.

From the consensus of the group..... cutting in the very cold winter period does not reduce the moisture content enough to make any difference.... at lest in Red Pine.

Yeah, blue stain is always a balancing act and we have that pretty much under control. The bark beetles are always "the competition" sawyers.... but we deal with them.... no biggie. If a few logs fall to beetles, we just cant them up to 6x6's and use them for raised beds or make them into 4/4 boards and use them as floor boards, siding, or whatever we need covered.

It is always so helpful to see what others are doing and get input from others that have already "been there"!!!

Thanks again!  
-Dad2FourWI

[randy d]

we live in southern Price county and we have a nice bunch of mature Red pine and we cut and sawed all last summer we did have some fungus trouble we bought a four foot ag fan and used it to surface dry our lumber that helped a lot good luck with your pine.      Randy