Try Indoor Gardening Projects for Rainy-Day Fun

Need a good science fair project idea? Or something fun to do with your kids on a rainy day? Through indoor gardening, parents and teachers can interest kids in applied life sciences such as botany, horticulture, and ecology. And it can't come too soon.

In 2000 the National Center for Education Statistics (NCES) tested the science proficiency of 47,000 public- and private-school fourth-, eighth-, and twelfth-graders. The results weren't encouraging. Only 29 percent of the fourth-graders and 21 percent of the eighth-graders scored high enough to be considered proficient or better, and just 18 percent of U.S. high school students were considered proficient in science.

By conducting their very own hydroponics experiments, your kids will get hands-on experience with plant life cycles and nutrient use-and they'll have a lot of fun, too! Here are just a few ideas to get you started.

Just the Facts

Can plants grow without soil? Absolutely. While soil anchors plant roots and provides support in traditional gardening, no soil is necessary for hydroponic gardening. In soilless gardening, as long as plant root systems have access to fresh, nutrient-rich growing solution, plants thrive. Why? While plants grown in soil expend a lot of energy looking for water and nutrients, plants grown in hydroponics systems get just what they need delivered right to their root systems-meaning hydroponically-grown plants get to expend most of their energy growing rather than looking around for their next meal.

Planting for Preschoolers

To teach very young children about soilless gardening, all you need are lettuce seeds, a shallow, glass bowl, a natural sponge, and a mild hydroponic nutrient solution such as Agro Nutrient ( 5-7-5 ). Mix a small quantity of nutrient according to package directions and pour over the sponge in the shallow bowl. Be sure that plenty of nutrient solution is always available to the sponge by keeping the solution level topped off in the bowl. Next, carefully sprinkle pre-moistened lettuce seeds onto the sponge. Place in a sunny, southern exposure or underneath a full-spectrum fluorescent grow light and make sure the sponge stays moist. In just a couple of days, the sponge will sprout-demonstrating that plants don't have to rely on soil to develop.

It's Elementary

With older kids, it's fun to compare the progress of plants grown hydroponically with that of plants grown in soil. You can easily conduct a side-by-side experiment with one standard tray filled with moistened garden soil and one Sunleaves Float & Grow. The Sunleaves Float & Grow includes a standard-sized propagation tray fitted with a reusable Styrofoam insert containing 55 specialized, inert growing plugs.

To get started, mix a mild solution of Agro Nutrient or another hydroponic nutrient of your choice and fill the propagation tray until its Styrofoam insert floats. During the experiment, be sure to keep the nutrient solution topped off to this level. Give the grow plugs enough time to absorb some of the nutrient solution and then plant your seeds. Plant an equal number of seeds in the tray filled with garden soil and make sure the soil stays moist throughout the experiment.

Now afford both trays a spot in a sunny, southern exposure or underneath a full-spectrum fluorescent grow light and keep notes about the plant growth you observe. Which plants grow more quickly? Do some plants look healthier than others?

Want to try something a little more advanced? One interesting variation on this experiment involves two Float & Grow trays, a simple aquarium pump, plastic tubing, and an air stone. As in the last experiment, you'll be growing the same types of plants side-by-side. The only difference? One set of plants is grown in the regular Float and Grow while the other set is grown in a Float and Grow augmented with the aquarium pump. Will one set of plants demonstrate speedier, more robust growth than the other? If so, why?

Prepare a mild hydroponic nutrient per package directions and add equal amounts to both trays until their Styrofoam inserts float. Allow the grow plugs enough time to absorb some of the nutrient solution and then plant your seeds. Now use the tubing to connect the aquarium pump to your air stone, and place the air stone at the bottom of one of the propagation trays. Plug in the pump to gently aerate the nutrient solution. You'll notice the plants growing in the aerated nutrient solution outperform those growing in the unadulterated hydroponics tray. That's because, aside from nutrients, the aerated solution provides additional, much-needed oxygen to the root zone.