The tone of the article is demonstrated here:
This notion—that it is agreeably possible to do good (school gardens!) and live well (guinea hens!)—bears the hallmark of contemporary progressivism, a kind of win-win, “let them eat tarte tatin” approach to the world and one’s place in it that is prompting an improbable alliance of school reformers, volunteers, movie stars, politicians’ wives, and agricultural concerns (the California Fertilizer Foundation is a big friend of school gardens) to insert its values into the schools.As you might expect, Mr. Freese is not happy with the article. He makes some points. I'm not sure that 1.5 hours a week is all that significant. And the logic for blaming gardening for poor test scores at the original school isn't particularly good. But on the whole I'm more on Flanagan's side than Freese's. There's also a post at Yale Sustainable Foods attacking Flanagan, with links to a couple other sites with attacks, and lots of comments.
Bottomline: while I concede gardening could serve as a way to teach lots of stuff, I very much doubt it's done that way in very many cases. What you're asking for is a teacher who not only knows the academic material, but is also a good and committed gardener. We don't have a surplus of the former, and there's sure to be a shortage of the combination. So, any teacher who wants to do gardening as a teaching method, fine, more power to her/him, but not as a requirement in the curriculum.