Kidsgardening.org has a great resource for teachers that not only contains sample lesson plans for educating students about bees, butterflies, and how to have a bee-free barbecue, but that also connects their classrooms to others that are experiencing the marvels of gardening.
Here's an example of taken from the Web site:
My fourth graders love to garden! From doing experiments to growing bulbs, flowers, and vegetables, my class spends 2-3 months both inside using our grow bed and outside in our garden. The local conservation commission provided daffodil bulbs last fall for the kids to plant. Right now (April) we are measuring and graphing their heights as they grow. We also graph the temperature as spring approaches starting in March.
The National Gardening Association is also offering an online course for K-8 teachers titled, "From Seed to Seed." For more information click here.
