I set my fence posts in a solid concrete collar so they’d never move: when I pulled the first one out three winters later, I saw what had formed right at ground level
That protective concrete collar you carefully poured around your fence post might be slowly destroying it. Three winters later, you’ll find a dark ring of rot exactly where the post meets the concrete—and the culprit isn’t what you’d expect. We explain why concrete turns against wood and how to build posts that actually last.