re: How long does it take for a acorn to sour or rot?

If you are talking about collecting in hopes to plant it this coming spring, the ones that have been on the ground for weeks are probably no good. When acorns hit the ground, there is a high chance they get eaten by deer, squirrels, or even insects. If you see a hole in an acorn, even a very small hole, insects have gotten into it and it’s no good to plant.

If you want to collect to plant, it’s best to look between late September-approx. early November when trees are actively dropping.

With that being said, this has been an absurd year as far as acorns go. I know of shumards that are still green currently and dropping still. That should all be done after the weather this weekend.

If you are looking to collect and plant, just perform a float test on them and that will tell you if they’re still good or not.