Earth Day is this Wednesday, and there isn't a more perfect time to inspire little green thumbs with little green gardens. In the spirit of Earth Day, here are two projects that use recycled materials to make mini-gardens. Empty 2-liter bottles make excellent terrariums. Kaboose.com has a straightforward tutorial for making one bottle into a plastic terrarium This is lots of fun, because it requires almost no maintenance once everything's put together, and your students can see water condensing and precipitating through the water cycle. If you're feeling adventurous, you can add another tier to create a combined aquarium-terrarium. The connector is the middle of a third bottle. Just squeeze the bottom bottle a little to fit it inside the connector tube. Place the top bottle into the connector upside down.
You can also use up plastic Easter eggs as tiny planters with the egghead eggshell tutorial also from Kaboose.com.
If you want to embark on a larger gardening project, check out my previous post on school gardens.
Images from my collection and Kaboose.com