Grow With the Foam

Hydroponics is a method of growing plants without soil. Instead, one uses a mineral nutrient solution to deliver necessary nutrients to the plants. Plants grown hydroponically need a growing medium for support. Rock wool is one of the most common growing mediums used. This medium is effective in commercial settings. However, in smaller systems, it would seem more environmentally friendly to use something more readily available, perhaps even recycled as a growing medium. Would packing peanuts provide a safe, effective, and environmentally friendly alternative to traditional rock wool used in hydroponics? My hypothesis is that recycled Styrofoam packing peanuts will provide a comparable growing medium to rock wool at a much reduced price. I set up my experiment in two 10 gallon aquariums. A trial was composed of five cuttings (~7 cm long and a mass of between one and two grams) of German Ivy, Senecio mikanioides, placed in mediums of rock wool and chopped up white, pink, and green packing peanuts, resulting in a trial consisting of twenty plants. I conducted four trials. I found that the packing peanuts were statistically a comparable growing medium to the more expensive rock wool.