Donald,
Adding a small, intermittent fan also helped me avoid damping off. But I think the fast-drying soil surface helped the most.
I have some photos of trays, inserts, and prop trays in a blog post, but I don't know how to create a link to just one post within a blog.
Does this "permalink" work?
http://garden.org/blogs/entry/...
Or, if you go to my blog, page down to near the bottom to see this post.
Maybe you can go here, and then search for the title?
http://garden.org/blogs/view/R...
Title:
"Plug Trays, Inserts and 1020 Trays"
Date:
