"You're making a big mistake," my father said some 20 years ago when I told him I was not going to renew my teaching certificate. He was angry, and he let me know it. We argued for days about my not wanting something I would never use. I was in my 40s and a long time out of college. And yet he was furious…

I saved the receipt. I stuck it in a gardening journal, which I began with vigor 10 years ago. I'd taken a course, and Kristen, the teacher, said we should all keep a gardening journal. So I did. For a while.

That first year, I cut and pasted pictures of every flower I planted. Little Leo Leopard's Bane. Osteospermum. Dunkle Schone Aster, which I described…