Indiana Greens, All-Year-Round
This winter, after the local growing season ends, mid-north Indiana restaurants and grocery stores will continue to enjoy crisp, vibrant produce in their commercial kitchens. Grown in Tippecanoe County all year round, Purdy Farms has built a scalable, solar-powered hydroponic farm producing leafy greens such as Romaine and Butterhead lettuces as well as fresh herbs like Italian Basil. Starting this fall, k-12 schools will be able to join Fresh Thyme Market and Purdue University’s 8Eleven Bistro in offering students an abundant selection of delicious, locally grown lettuce.
Unlike conventional farms, seeds in hydroponic systems grow indoors without the use of soil and can be grown in any season or climate. The Purdy family’s hydroponic farming project started in the middle of the COVID lock-down, when Purdue Alumni Joanne Purdy (ME ’89), and her teenage daughter, Carolina Mendez, began looking for ways to grow crops that are less dependent on traditional weather patterns.
In hydroponic growing systems, plants obtain essential nourishment from nutrient-rich water and receive energy for photosynthesis from high-efficiency LED lights. The indoor climate is controlled by a series of sensors that track environmental conditions such as temperature, humidity, and light. Farmers can program computer software to create a consistent, ideal growing environment that automates growth recipes and adjusts pH, electrical conductivity, and carbon dioxide levels in real-time.
Purdy Farms built the hydroponic farm facility inside a large barn on a row crop field the family has been cultivating for more than 150 years. Despite having a wealth of experience growing food, the technology learning curve was steep. Making the new environment operational involved installing many pieces of intricate equipment such as ultraviolet and reverse osmosis water filters, ultrasonic tank sensors, flow transducers, and pressure-regulated drip emitters. Programming the system was a trial-and-error process of adjusting nutrient ratios, dosing rates, and light intensities. Ultimately, the farming team configured a control system to optimize plant development and to grow approximately 10 tons of produce a year.
Like traditional farming operations, optimizing crop yields and controlling costs in a hydroponic system involves continual experimentation to increase productivity and ensure high product quality. For instance, in late spring Carolina and Joanne ran test trials with different types of seeds to determine the hardiest and tastiest lettuces for a short, six-week growing cycle. To reduce electrical costs and further enhance sustainability, they obtained a federal government solar grant and installed two 38.5 kW solar arrays alongside the facility. Solar panels now generate electricity to power cooling systems, circulating pumps, and LED lights which operate 24 hours a day, 7 days a week.
Today, Purdy Farms’ produce can be found in Sunspot and D&R Markets, as well as restaurants like Lafayette Brewery Co. and McGraw’s Steak House. Thanks to local production, there is no longer a need to rely solely on importing greens from warmer, distant climates like Mexico and California during the winter months. The family offers Indiana students and teachers the opportunity to visit the hydroponic facility throughout the year to learn about the technology and participate in the ongoing educational experience. Joanne, Carolina, and the team are always excited to give tours and share their passion for sustainable farming and for growing food a little closer to home.