Place a handful of dry kidney beans in your plastic container. Cover with lukewarm water. Allow them to sit for an hour.
Pour potter's soil into your plastic planter, stopping several inches short of the rim.
Push the kidney beans into the soil, using tweezers to prevent the oils in your hand from contaminating the beans. Make sure the beans are embedded at least an inch into the soil, according to instructions from Purdue University's Department of Horticulture. If you plant more than one bean per planter, make sure that they rest at least 6 inches apart.
Cover the bean holes lightly using soil.
Water the beans once per week, in the early morning, with about 1 inch of water.
Introduce your experimental conditions. For example, if you want to find out how music affects the growth rate of bean plants, then set up a radio and play music for one set of bean plants. Leave one control group unaffected, so that you can compare the growth rate of the musically-affected plants with plants for which you didn't play music. Observe and note the difference.