Just thought I'd put this out there if anyone else was looking for the most cold-hardy hybrid chestnuts around (as I have been).

I planted two Oikos ECOS hybrid chestnuts about 5 years ago on my dad's farm, and just checked on them this weekend for the first time this year.

Last year, they WERE 8 ft tall and bore nuts the past two years.

Yesterday they were sticks in the ground, resprouting from the roots, winter-killed by the harsh winter we had in the upper Midwest this past year. My brother's best guess was that we hit -35F or even -40F once or twice (this was a few miles from Holdingford, MN, pretty much dead-center in the state). They were also in a somewhat exposed location, since my dad cleared out some dying trees in the windbreak.

I let my brother rip them out with the tractor. Oh well, I'll give the trees from Badgersett a try next time.