In Fall 2022, Housing Dining & Hospitality (HDH) on the UCSD campus gave Roger's Community Garden jurisdiction over the hydroponics towers behind 64 Degrees Dining Hall located in Revelle College. Having been decommissioned years prior, RCG members were excited to get them back up and running.
Hydroponics is a soilless farming method that uses water and nutrients to grow plants in a limited space. This method has excellent Water Usage Efficiency (WUE). The characteristically closed-off, white structures prevent both evaporation and drainage loss. Whereas some hydroponics set-ups are horizontal in flood beds, these hydroponic towers are vertical with trickle irrigation. Nutrient-rich water is pumped from the troughs up to the top of the tower, where it cascades down onto plant roots through perforated pots.
RCG members started off experimenting that Winter with just one of the fifteen towers operating. Materials were ordered, seeds were sown, and not too long after, the first seedlings were transferred into the hydroton pellet pots and placed in the towers. Finding the right ratio of nutrients to provide proved difficult. Other issues faced were leaks and pump energy usage issues that caused the tower to periodically stop pumping water. The combined issues caused our mint starters to dry out completely. It was a rocky start.
In the Spring, new methods were tested. The hydroton pellets, which are the type used in our aquaponics system, were replaced by grow cubes, a denser, softer material that holds water better than the pellets. The pump issues that cause the tower to shut off persists, but this has been mitigated by our members, who visit the tower daily to ensure it is in working order. Our members have noted that "woody" types of plants do not grow well in the towers and are to be avoided. Leafier plants are preferable.
Currently, greens and green onions have done extremely well in the tower, even amidst the summer heat. Our project lead hopes to open more towers in the Fall and experiment with nutrient ratios.
Row of fifteen hydroponics towers.
First official RCG hydroponics trial run. Disasterous.
Tray of hydroton pellet-filled pots with seedlings.