Mold forming on roundwood timbers after stripping bark

Hi all,
I am having some mold problems on roundwood timber I am hoping you might be able to help with.

Building is an octagonal structure, using roundwood timbers for the posts, beams, and rafters. We are located in the maritime Pacific Northwest. When I initially cut down the trees for this project, it was late spring. Soon after cutting them down, I used a draw knife to strip the bark, then left them in a part sun-part shade area to dry out sitting on some alder logs (as stickers). They were not rained on. In late summer we started seeing some black moldy growth on many of the logs (again... no rain). We washed all the logs with soap & water. They continued to get moldy. We tried treating them with white vinegar/water mixture & it did not seem to help. The only timbers that did not mold were ones where I stripped the bark later (brutal process where the bark & underlying wood had fused strongly together making the draw knife work very, very difficult; wood after stripping is very dry). The timbers that did mold were the ones that I stripped right away (draw knife more easily gets under the bark, exposing a very slick wood surface). Wood is doug fir & hemlock.

Any ideas on what I can do to prevent this from happening in the first place?
Any ideas on how best to 'treat' the ones that did mold?

Thanks in advance for your time & help. Much appreciated.

Spring is when there is the most sugary sap flowing up from the roots, so cutting trees then starts off with the worst possible conditions for mold. The best time for cutting trees for most any use I know of is late fall or winter, when the sap is all down in the roots. Debarking then, or possibly as soon as spring thaw hits (I don't know if waiting that long is detrimental), would get the cleanest job, not as easy as sap-filled wood, but you have seen the results of harvesting sap-filled wood.

My thought is to not worry about it.  I think you'll notice that soon slugs will start arriving to eat the mold. Presumably there's other things that will eat it too. Worst case scenario, when you're ready to use the timbers, give them a good sanding to remove the outer layer with the mold.

Hi Brian, that's pretty typical. It'll go away as the wood cures. Are you taking moisture readings? We had a bunch of fresh cut go green and fuzzy and all the neighbors said it was ruined and when it happened to them they threw it in the firewood pile. A year later it is beautiful silvery grey and a joy to work with. Patience, it stays pretty wet here but I've seen some old barns around here that are still standing from Homesteaders.

The same thing has just happened to me over in the UK with a blue cedar that I had felled. I do hope they will come right in the end so I'll keep my fingers crossed and not burn it.

Use borate/borax. Mold may still grow on surface. I have also  used sodium per carbonate- let that soak in a hot water slurry and scrubbed. Basically, you will have to sand/grind off the surface layer when you are said and done l.

I agree with one commenter that the issue is likely the sugars and other living sap consituents in the layers just under the bark since you peeled the trees in the spring.  It seems to me that it might help (don't know about now, but perhaps in future if you do more of them) to soak the logs in water for a period of time after peeling, so that the stuff will leach out in the water.  Such a procedure is recommended for processing bamboo.  After a few weeks or a month, pull the logs out and let them dry.  
    Borax and/or boric acid are your friends when it comes to mold.  Dissolve either or both to saturation in hot water and paint on.  This will kill all kinds of mold and wood rot, and make the wood repellent to termites and ants as well.  You can wipe off the white crystals that form and paint over that if you like, provided it's all completely dry.  I've used this both to kill existing mold and prevent it in advance.