Potted Gardens!

We love plants at our house. Thing-one seems to have a natural green thumb and thing-two loves to eat our fresh vegetables. I love watching my kids grabbing lettuce and spinach from out garden and cramming it into their mouths. Victory! Talk about a great way to teach and reinforce good nutrition. We have conversations about how healthy those vegetables are and so yummy too. 
A vegetable garden is also a great science lesson. In fact we have been focusing a lot on Botany lately because thing 1 and thing 2 have become so fascinated by it all. A garden is a great way to teach that! They learn all about the different parts of the plant-- planting seeds, harvesting (which part of the plant are we eating?), watching it grow (the pea plant grows differently and looks differently from the broccoli plant), and even when they accidentally uproot a plant while trying to pick off something yummy. They also learn about the things a plant needs to grow. You can slip in a very simple  lesson on photosynthesis here- the plant uses the sunshine to make energy so that it can grow. Just like food helps you to grow. 
The best part is, you don't even have to have a yard. or even know that much about gardening to make this a project with your kids. Our "garden" consists of a few pots on the back patio of our apartment. So far we have successfully grown spinach, lettuce, and broccoli. Our pea plant is growing well, but we'll see if it ever produces anything. 
The one thing I have found from personal experience is that vegetables don't grow well without sun. So if you don't have a sunny spot you might want to try a different type of plant. Maybe a pot of flowers. There are several types of flowers that are edible so you could look into that too.
Go have some fun with your kids!