Watch a plant grow.

I recently purchased this little ceramic dog grass growing kit at CVS on clearance for 75 cents.  One of the things on our Summer Fun list is to watch something grow.  We put the dirt and seeds inside the puppy and then watered it.

A day or two later, we had grass!  We check it every day to see how long the grass has grown and to water it again.  It's a fun, and very simple activity.