Yeah, my first thought was damping off. And the chickens may be in
there because of grubs/cutworms, something like that.

Don't give up. Plant something bomb-proof. I have a great crop of
vetch, as a covercrop, to help my soil. Get your soil tested and be
sure there's a good balance of nutrients, and not too much of anything.
What's the pH?

And I'm wondering where you are still...Victoria, is that British
Columbia, or Australia, or...?

Container gardening is a good way to get veggies. I had good tomatoes
in my #5 pots.

bahB