Help kids see how plant grow! (Or if you're short on kids just do it for yourself - it's pretty cool!) :: Science for Kids: Observing Plant Growth with Bulbs (with a FREE printable observation sheet!) from Buggy and Buddy
Soil Erosion Experiment This might look like such a simple experiment but it will definitely show the importance of having vegetation covering the soil to your kids! They will love this hands on exper (Garden Step Long)
How to make a plant in the bottle: Illustration shows cutting the top of one bottle and bottom of the other, taping them together to form a bottom reservoir into which a string dips to provide water to the soil in the upper bottle.