So, we grabbed a couple holly logs as a target of opportunity. No chance to wait until cooler weather. It was get 'em or leave 'em.

So I cut some turning blanks and they looked okay. On the outside, at least. Despite having a fan on them and being subjected to indoor humdity (~50% at all times), after a week they had sapstain through them entirely.

We also cut some 1" boards. We neglected to re-cut the ends (since they weren't cracked and were anchorsealed) and temporarily stacked the boards by leaning them against a tree. There was a 6" band of sapstain 1/4" deep the next day where the board ends were touching the boards.

So I decided to test some various chemicals I had on hand to see how they worked. After a day here's what I've found--

Chlorine bleach in water at about 1 to 5 seemed to spread the stain faster.

Propiconazole (a popular fungicide) seemed to do nothing.

Physan 20 (algaecide/fungicide) turned the wood a little green on the surface, and seemed to repel the fungus initially -- but had no lasting protection, as the test piece got fungus on it from handling (see picture!).

Boracare (at $20/gallon mixed at the lowest rate!) seemed to hold it off for a day -- maybe.

Baking soda, which is reputed to fight sapstain, made it grow faster. Way faster. The test piece was completely green within six hours, 1/8 deep at least.

Next thing I'm going to try is timbor, just because it's cheaper.

Cultural control seems to work somewhat (wash the piece, put it outside by itself where it doesn't get exposed heavily to spores while it's wet). It's impractical and I can't find anything to wash the pieces with other than water, and it doesn't scale well.

Any ideas as to a chemical biocide for sapstain on holly?

IMG_20171023_215049861_HDR.jpg