Near the center of Tucson sits Howenstine High Magnet School, which closed in 2013. The space hasn’t gone to waste, however. The schoolyard’s athletic fields now house a 10,000-square-foot greenhouse operated by Merchant’s Garden, filled with vibrant greens and thousands of tilapia.
While fish farming seems counterintuitive in the desert, it’s a crucial part of a symbiotic process to grow quality plants. Thanks to the science of aquaponics and hydroponics, Merchant’s Garden saves up to 90% water in comparison to conventional farming and brings the farm to the city. Additionally, Merchant’s Garden current greenhouse has the capacity to produce a half-million pounds of produce and 10,000 pounds of tilapia per year.
Tilapia is relatively new for Merchant’s Garden — although the tilapia has been part of the greenhouse, they only recently became available for sale to restaurants.
Before the fish became ready for the kitchen, they were a fundamental component of the symbiotic process known as the aquaponic nitrogen cycle. Fish generate ammonia-rich waste, which special bacteria take advantage of. Nitrosomonas oxidize the ammonia into nitrites, then nitrospira oxidize the nitrites into nitrates. The plants soak up the nitrates, and finally, the water cycles back to the fish tanks. In layman’s terms, the fish fertilize the water, microbes turn the fertilizer into plant food, then the plants clear the water.
Of course, the process has other factors to control, such as temperature, humidity, and pH. If the system is out of balance, the fish won’t be happy.
But now that the systems have been refined, the computer-controlled facility can consistently yield quality tilapia and out-of-season produce year-round.
The tilapia have only just entered the market, so they haven’t made their way into a restaurant yet. Merchant’s Garden is currently in discussion with a handful of restaurants to feature the tilapia on their menus. With how conscious Tucson’s culinary scene has grown, don’t expect to wait long before you find locally-grown tilapia on a plate or in a fish taco.
In the meantime however, you can find the produce throughout Tucson.
The lettuce is harvested within an hour of being delivered to restaurants. Find it presented alongside burgers at Diablo Burger. The red bok choy is on the shelves at Time Market, but can also make an appearance on the menu via specials such as the Chicken Bok Choy Salad. Additionally, you can find Merchant Garden’s lemon basil in the Caprese Bruschetta at Ermanos and the Thai basil throughout Senae’s menu. The basil doesn’t even need to travel a full mile to reach Barrio Bread and make it into their Kalamata Olive Fougasse.
Restaurants to Find Merchant’s Garden Produce
- Time Market
- Rincon Market
- Fanny’s Cocina
- Ermanos Craft Beer & Wine Bar
- Senae Thai Bistro
- Urban Fresh
- Westin La Paloma
- Canyon Ranch
- Diablo Burger
- Barrio Bread
- Reilly Craft Pizza + Drink
- Lindy’s on 4th
While you’re dining at one of the above restaurants, keep an eye out for one of the ingredients below.
Merchant’s Garden Product List
- Red bok choy
- Thai basil
- Genovese basil
- Green leaf lettuce
- Romaine lettuce
- Red leaf lettuce
- Butterhead lettuce
- Citrus basil
For more information, visit merchantsgarden.com.