We started by buying a basic pack of green bean seeds from the store. The next step is to fill several same sized cups of potting soil. We went with two different sized cups as a test to see if cup size has an effect. Basically we are running the experiment twice. Each cup was filled with exactly 1/3 cup of a liquid. Liquids used were tap water, milk, orange juice, Coke, and orange Powerade.
My daughter will monitor the cups each day and record the first day a sprout appears above the soil line. At that point, the height of the green bean sprout will be measured. The goal is to determine if green beans grow best in water or a different liquid. The germination time for these green bean seeds is 7 - 14 days, so nothing will happen for several day.
This is an exciting time in our house. Our 8 year old is super excited to be doing an official science fair project and is looking forward to the presentation night in about 3 weeks. Hopefully she has some good results to show. Even if the experiment does not work as well as planned, there's still much to be learned. When things go wrong, it's not necessarily a bad thing in science as the disappointment can still lead to knowledge gained.
If your child brings home a flyer about an upcoming science fair, don't ignore it. Encourage your child to participate and search the web for ideas. There are thousands out there!!!