As part of our NGA acquisition, we also obtained all the content that has been developed over the years by this great organization. I'm frequently stumbling onto hidden treasures, and recently I found a really neat educational online curriculum that was developed in the early 2000s.
I put it back together and posted it to the site this morning. You can check it out by clicking on "Learning Garden" in the left hand menu bar.
It's all great, but n particular check out the "From Seed to Seed:
Plant Science for K-8 Educators"
http://garden.org/onlinecourse...