Now is a great time to start talking to the wee ones about seed germination — how a seed grows into a plant. How does it "know" when to grow? (A seed is actually dormant, waiting for temperature and light cues, as well as other factors, like moisture in the soil, to let it know that it's time to grow!)
Growing a small garden (or a garden box which is what I did when we lived in an apartment) can be a great way to show kids how life starts and thrives. In an inadvertent demonstration of how photosynthesis works, last fall our beautiful pumpkin patch was decimated when our dog Charlie decided to eat the leaves off the vines. While a bummer given that the vines looked promising and had already started a beautiful pumpkin, it was a clear indication that without its leaves, the vines couldn't go through the process of photosynthesis and thereby provide energy for the plants. This year we're hoping to expand the garden a bit so the vines have a chance to grow out a bit and we'll provide slightly better fencing so that Charlie doesn't get to indulge her taste in gourd leaves.
While we wait for the seedlings to come through (some plants are easier to grow inside at first where they can be protected for a while until they're less vulnerable to the elements, or the Charlies), check out some inside science. (More outdoor science posts to come as the creepy crawlies come out and the plants truly begin to bloom.)
Sesame Street has recently launched a "Little Discoverers" STEM (Science Technology Engineering Math) site to introduce the toddler-to-PreK set to science. It's got fun and simple demonstrations of how simple machines work (like pulleys), matter phase changes, and how the scientific method works (on a basic level of course). One of the highlights of the latter is when Oscar decides to run experiments on his unsuspecting neighbors on what is most "smelly," "loud," and other Grouch-favorite annoyances.
For a somewhat older crowd, I highly recommend the re-imagined Cosmos series with everyone's favorite astrophysicist, Neil DeGrasse Tyson. It is an amazing treat to the science senses and it's just a cool trip into the universe, its formation, our own solar system, and Earth, and I'd say existence in general.