An Experiment in Growing Hydroponic Tomatoes

GrowingHydroponicTomatoes

Gardening has been a hobby of mine for a very long time. In fact before moving into the condo that I currently live in, we lived on 5 acres and I had a gigantic garden and greenhouse. Gardening can be a great maker experiment. From planting in the ground to raised gardens to pots. Choosing the seeds or plants. Watering systems. Tilling methods. It requires using the engineering design principle. Trial and error. Taking a risk. And then if your garden fruits, you have to determine what to do with the harvest. Crack open your cookbook and pull out those jars, you can learn to can your produce. Or freeze it. Or use it up. Or sell it. Or give it away. Or trade it. Moving into the condo required me to downsize my quarter acre garden and get creative. At the same time that I moved, I had been dabbling in hydroponics in our Maker Space at school. I got excited about doing hydroponic gardening at home and that’s what I did this past winter.

With the weather warming, it is almost time to shut down the hydroponic operation in my basement and focus on planting outdoors. One experiment I’m trying is to compare the growth of tomatoes grown hydroponically with those planted in soil. I began the tomato seeds on March first and have since transplanted them once. Three tomatoes were transplanted in deli cups and a fourth was transplanted in a five gallon bucket with perlite as the growing medium.

I have tried to treat the four plants the same with keeping them outside and giving them water. The difference is that the plant in the five gallon bucket receives a nutrient solution 4-5 times daily poured from a reservoir. As the unused nutrient solution flows down through the perlite it returns to the reservoir through a drain so it can be re-poured at a later time.

I expected that the hydroponic plant would do much better than the plants in soil, but this has not happened. As of this morning, the plants in soil are about two times as large as the plant in the bucket. In about a week, I will transplant the soil plants to the outside. My guess is that they will experience some transplant “shock” and their growth will be slowed.

I am also wondering if the nutrient solution should be tweaked for the hydroponic tomato. I used the same formula that I used for growing lettuce in my basement under lights during the winter. I believe that because tomatoes need green growth as well as fruiting growth that it may be necessary to add more phosphorus. The nutrient balance I am using is 19.5 – 18 – 38 so all of the nutrients are there. I am also wondering if the concentration is correct.

I just got an E.C. meter to test the conductivity so I will need to learn how to use that. I’ll keep you posted but for now, more study is needed. See what I mean about making and gardening as a perfect maker experience!

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