The kids loved watching bean seeds sprout. We put five beans in a ziploc bag with a folded wet paper towel. The bags were taped to our classroom window (with names written in permanent marker). Of course we also read "Jack and the Beanstalk
Designers' Own Gardens: Ideas from Laura Crockett — The Gardenist
Natural Weed Killer 1 gallon vinegar, 1/2 cup salt, dash of dish washing detergent (makes it stick to the weeds). Mix well, spray on weeds in the morning, rejoice in their death that evening. This works best on a sunny day. @ its-a-green-life
Parts of a flower in 3D - a good science lesson for Kansas Day, though the blog post is no longer available
Baking soda neutralizes the ph in the soil and nothing will grow there. use baking soda around all of the edges of flower beds to keep the grass and weeds from growing into beds. Just sprinkle it onto the soil so that it covers it lightly. Do this twice a year - spring and fall. Awesome!
Kids can learn how to garden, get them to be involved with the nature. They could learn about how the plants grow and what do plants need to survive.