Drying black walnut, bug free

Practices for preventing infestations while air-drying lumber. November 29, 2000

Does black walnut need any insect treatment to prevent infestation when air drying or does the wood contain its own natural defense? The odor of the wood is quite pungent.

Forum Responses
I recently slabbed a black walnut tree that had been in ground contact for about a year or so. There were termites under the bark and in parts of the heartwood that had remained wet. So, while this doesn't directly answer your question, it would seem that a bit of care should be taken when drying any wood--don't allow ground contact of the drying wood or any wood it is resting on, and keep an eye on the wood as time goes by. It should be okay, but wood as nice as black walnut is worth taking care of. I would err on the side of caution--some bug spray on the surface might be useful.

I've air dried a lot of black walnut and have never had any problems with the heartwood attracting bugs of any sort. At the same time, some elm sapwood nearby in the pile attracted the powder post beetle, so there were bugs around.

I have had a black walnut log on the ground for 10 years and when I sawed it I saw no bugs in the heartwood at all. It was amazing to me but I think the heartwood is extremely resistant to pests of all types because of the juglones in the wood.

Power post beetle (PPB) will get into the sapwood of the walnut. When the bugs are ready to come out of the lumber to do their thing (have sex!) they can and sometimes will travel through the heartwood. I treat all of my fresh sawn lumber with an approved insecticide such as lindane, particularly the sapwood. Heartwood has no food for the PPB.

Lindane dries on top of the lumber. So any PPB that is already in your walnut will be unharmed by the lindane until he/she comes out. Once again, that is why I only purchase fresh sawn lumber. If you choose to go this route, use common sense while using lindane--long sleeve shirts, rubber gloves, etc. Hit the shower after you are done. When the lumber is dried, use a DC while planing. Since lindane is superficial, once 1/32" of the surface has been removed the lindane should be gone. Or you can sell your sapwood lumber as antiqued bugged lumber on ebay.