I had been slated to give a presentation about urban farming at an entrepreneur’s conference, and so decided to visit a nearby urban farm to get some up to date information about the state of the industry.
Fortunately, one of the most successful urban farms in the USA was located a mere 1.5 hours away, in Philadelphia, Pennsylvania.
GreensGrow Urban Farms started in 1997 when Mary Seton Corboy and Tom Sereduk decided to set up hydroponic systems to grow lettuce in a former galvanized steel plant in the Kensington area of Philadelphia. They were joined several years later by David Prendergrast, who was kind enough to show me around the farm and answer all my questions in quite good detail.
The entrance to GreensGrow Urban farms in Philadelphia. Click on thumbnail to view full image.
The farm itself is located in what looks like a mixed commercial/industrial/residential neighborhood. A tall steel fence surrounds the 1 acre property, and from the outside it looks remarkably like one of the many garden stores that you can easily find in suburbs everywhere.
It’s when you step inside that you quickly see how different this farm is from a simple garden outlet.
The CSA station in the urban farm. Click on thumbnail for full image.
One of the first structures you see is a shed with a big sign that welcomes the farm’s CSA members. CSA usually stands for “Community Supported Agriculture”, a concept where people buy a “share” in a farms’ season and each week get a box of produce and fruit produced on the farm.
GreensGrow has tweaked the moniker to “City Supported Agriculture” in deference to its central urban location, and expanded the process to incorporate meat and dairy products, as well as vegetables, from its own farm as well as surrounding community and rural farms. Its subscribers have grown from a few handful to more than 400 people today, and the farm was forced to limit new subscriptions due to the overwhelming success of this model.
In addition to their innovative CSA program, the urban farm produces vegetables for retail chains and restaurants in the area, and even sells flowers and other crops to walk-in visitors to the farm.
The farm produces its own biodiesel from waste cooking oil from surrounding restaurants. Click on the thumbnail above to view the full image.
The farm also makes use of various renewable energy solutions. David Prendergrast showed me their biodiesel set-up, which is housed in a shed that also functions as a rooftop garden. They get their feedstock as waste cooking oil from the various surrounding restaurants, and use the resulting biodiesel to power their farm equipment and delivery truck. While we talked with Terry, the caretaker of the biodiesel apparatus, bees from the hives planted on the rooftop garden buzzed around us. The bees are meant to supplement the native bees in the area as pollinators for the various crops in the farm, in addition to producing honey.
The farm also uses solar power to drive a water pump. Click on the thumbnail above to view the full image.
The farm also has a lone solar panel, which is used to power a small water fountain. David explained that they plan to use more solar energy to power the various operations of the farm in future, and we talked about various scenarios for achieving this goal. Given the rapidly dropping cost of solar modules, I have no doubts it will soon be possible to turn the farm into a model user of solar power.
The farm makes extensive use of hydroponics systems to grow lettuce and other plants. Click on the thumbnail above to view the full image.
Probably the most interesting thing for me though was the hydroponic system that they had running near the back of the farm. As most anyone who has dabbled in hydroponic systems knows, the variations possible in such an apparatus is only limited by the bold imagination of the growers and the need for financing. In this case, the farm had opted for a nutrient film system, using long rain gutters as the trough and gutter guards as the framework to support the growing plants. Although there was nothing planted at the moment, it was an interesting sight nonetheless.
Plants are held in place in the hydroponics system by modified rain gutter equipment. Click on the thumbnail above to view the full image.
Protected by long hoop tunnels, the seedlings are first grown in plastic trays using oasis cubes as the media. They are then laboriously transfered to the final hydroponic set-up once they reach a certain size. Water pumps assure the continued flow of nutrient solution to ensure that the seedlings grow healthy and reach maturity.
Seedlings are first grown in trays, then transplanted when they are large enough. Click on the thumbnail above to view the full image.
Another fascinating set-up in the farm was a wall-mounted vertical hydroponic system that was attached to the side of one of the working sheds. Although much smaller than the traditional system they had near the back, it was just as ingenious. Slanted rain gutters were affixed to the wall one above the other, channeling water from the top to the bottom at the ends of the long troughs. A water pump provided the power to lift water from the pond to the highest point of the system. The reservoir doubled as a Koi pond, with the fish providing some nutrients to the growing plants on top. David run the system for me, and it was a joy to see the water sluicing its way from one rain gutter to the next, before falling like a miniature waterfall into the waiting pond.
The farm also has a new wall-mounted vertical hydroponics set-up. Click on the thumbnail above to view the full image.
Much less interesting to me personally were several chickens and a rooster that occupy a small portion of the farm near the street. It was an incongruous sight, to say the least, to see all these chickens pecking at the ground for food when right behind them loomed a parked jeep and a somewhat busy side street. According to David, the hens are always a crowd pleaser to the many kids that visit the farm.
The farm also has some chickens, some of which were donated. Click on the thumbnail above to view the full image.
The other notable thing that one notices when visiting the place is that most of the plants are grown on raised concrete and wooden beds. This is a fairly expensive way of growing plants, but it’s necessary because the farm is located right on top of what used to be a galvanized steel plant, and the soil in the area is not amenable to raising crops.
Plants are grown on raised concrete beds. Click on the thumbnail above to view the full image.
I finished my visit by thanking the very kind David Prendergrast for his comprehensive tour of the farm. I was heartened by the success of their decade long venture into sustainable urban agriculture, and fully appreciative of all the hard work and sweat that they must have put into making the farm so indispensable to hundreds of people in their neighborhood.