Kennesaw Charter Science and Math Academy
Elementary Garden Club Hydroponics SFE Blog Summary for 2015/16 project.
Michael Donnelly, Cobb County Teacher Master Gardener
Amanda Green, Amazing educator
Background: The Education Committee of Cobb County Master Gardener Volunteers, Inc. (MGVOCC), Teacher Master Gardener, Michael Donnelly and his colleague, Amanda Green, teamed up to develop a hydroponic and aeroponic gardening program for grades 1-5 at Kennesaw Charter Math and Science Academy in Kennesaw, GA. The Academy is part of the Cobb County Public School District. The collaborative effort enabled students in grades one (1) through five (5) to experiment with the basic requirements of plants in order to grow them successfully outside of the soil and to compare the effectiveness of growing them with roots in air or submerged in water
The teachers and students began the 2015-16 school year with some donated commercial hydroponic and aeroponic growing equipment, which consisted of two towers (aeroponic and shown in first photograph) and a water table (hydroponic, not shown). They were intended to be used in the classroom. However, additional funds were needed to purchase supplies and more importantly, some basic knowledge was needed in order to successfully grow the plants. In August 2015 the school received $140 in funds from MGVOCC for their gardening program (they have an outside garden as well). Michael Donnelly took this opportunity to question Cobb MG Linda Hlozansky, about hydroponics, but since the MG training did not include this study, MGVOCC saw this as an opportunity to further its knowledge of hydroponics. A separate equipment and supplies budget was requested for developing a hydro/aeroponics gardening program and was presented to the MGVOCC Education Committee, which approved a $300.00 budget and the program began. In exchange, the students presented Cobb County Master Gardeners the results of their “experiments” at the end of the school year.
- successfully grow edible plants with roots either in air, or submerged in water
- replicate consistent results
- discover less costly ways of achieving the same results (with less expensive equipment)
- expand knowledge base of Cobb County Master Gardeners in hydro and aeroponic gardening
The wonder in this project began with the uncertainty that plants could truly thrive without some type of soil medium. Though most students had some experience with gardening either at home or in our school gardens, those experiences were in traditional growing methods when it came to soil and light. Research wasn’t too difficult, the internet is full of videos, articles, and blogs on hydroponic growing, and our learning curve, though steep at first, was only slowed down while we got ourselves competent with the pH needs of plants and the methods in acquiring and maintaining proper pH.
The expense of quality U.V. lighting, and the limits in donations of funds and materials naturally set up the comparison between growing in natural light (in a window on a rotating base), and artificial light 9attached to the fixture and run on a timer. We decided on using “optimal summer conditions” and set the timers on 12-hour rotations.
Two unanticipated challenges we met along the way were pests, and premature bolting.
Without adequate scientific knowledge, we came to the assumption that the premature bolting (spinach from seed to flowering in 4-weeks) was most likely due to the “optimal lighting conditions” brought about by continuous exposure to 12-hours a day full sun.
Our pests came in two forms, aphids and fungi. How the aphids got in is unclear, but left unchecked by predation, aphids thrived and were a constant enemy of our young gardeners who chose soap water and manual labor as the best practice to safely cull the attackers without strong chemicals. The fungi was ignored except for extreme spots that were cleaned with towels and soap water. Neither of these foes was damaging to the overall success of the plant growth.
Maintaining proper nutrient density was a challenge since evaporation was pretty high and the need to replenish water seemed to thin the nutrient availability.
A digital meter was purchased to measure the initial density and nutrients were added in recommended ratios on regular intervals to maintain those levels.
Results/Conclusion: This is still an ongoing project, and as of this writing we have succeeded in optimizing plant growth by better controlling lighting and continually tracking the nutrient levels in the water. We now are reaching plant maturity in about 60-days. The aphid problem has not returned and in retrospect, we were storing plants purchased for our traditional outdoor gardens in the same room as our infested indoor plants. Those store bought plants were the likely source and care is now used to keep the indoor plants isolated to prevent re-infestation.
Fungi is an ongoing occurrence but we choose to see this as a byproduct of the environment that will not harm our efforts. So far it hasn’t.
Because these growing systems are maintained in our science lab and entry foyer all our 800+ students are aware of the project, and many more have had the opportunity to participate. Even greater are the number of students who have enjoyed tasting our rotating hydroponic crops such as chard, kale, spinach, various lettuce, and broccoli.
Because of the decreased growing time and increased growth speed, these students are also able to witness the entire lifecycle of edible annuals, from seed, to flower, to seed…