Thinking of greenhouses takes me back to my early childhood and my Grandfather Lamont’s small wood frame and glass greenhouse where he grew a mixture of ornamental plants and vegetables. I can still recall the earthy smell inside.

My next encounter was working part-time for my friend Art Abbott Jr. and his father in their old glass greenhouse located on the trial grounds of the Abbott and Cobb Seed Company in Bucks County, PA. The next exposure to greenhouses was as a graduate student at Cornell in the late ‘70s when Dr. Ray Sheldrake took me under his wing and introduced me to wooden-framed greenhouses he designed that were covered with two layers of plastic and had air introduced between the layers for better insulation. Ray also was also instrumental in developing the Cornell peatlite soilless mix with Dr. Jim Boodley. Both these inventions revolutionized the growing of bedding and vegetables in a greenhouse.

My first job in 1980 found me in the Department of Horticultural Science at North Carolina State University with Extension responsibilities for field and greenhouse vegetables. Most of the growers used single or multiple-bayed Quonset-shaped greenhouses made of metal pipes covered with double air-inflated poly. Some growers were using plastic mulch; most were using drip irrigation. Pests were like today’s, and I did observe some horrendous outbreaks of aphids where the tomatoes were covered with black sooty mold. This taught me the importance of scouting greenhouse crops and timely introduction of biological controls in its infancy back then or application of pesticides.

Nutrient film technique was used, which involved plywood ground frames in which a poly liner was laid. Water and nutrients were run through the system and back into a reservoir to be recirculated. We also had greenhouse butterhead lettuce growers using either homemade PVC system or commercially sold gutters and growing what they marketed as “living lettuce.”

The other interesting observation was the variety of heat sources I observed from large outside wood burners to the standard Modine gas heaters to homemade truck radiator units and even wood stoves in the greenhouse.

When I moved to Kansas State University, I was involved in research and teaching and did mainly research trials on greenhouse vegetables (tomatoes and European cucumbers) and then transitioned to high tunnels when I arrived at Penn State. The biggest thing I confirmed at Kansas State was how resistant the European cucumber varieties were to powdery mildew.

Now I realize that there are many very large greenhouse complexes in parts of the U.S. and Canada that supply a large amount of the vegetables we find in the marketplace. My friend from Mississippi State University, Dr. Rick Snyder (who was known as Dr. Greenhouse Vegetables) interacted with growers across the country. Recently I had a wide-ranging conversation with Rick and he said most of the greenhouse vegetable growers he worked with in the Deep South were smaller growers and that was probably the same for most of the country. He said most grow in soil, and with tomatoes, the large beefsteak is still the predominated crop, although we agreed that some of the newer heirloom varieties released by Dr. Randy Gardener of NC State University work well in the greenhouses, along with some of the newer smaller size varieties with an array of colors and shapes. He also said that the new smaller Beit-Alpha cucumbers are catching on instead of the long shrink-wrapped European cucumbers.

We talked about the large greenhouse operations around the country – anywhere from 40 to over 200 acres – and that most of those use rockwool as growing media, as it’s easy to handle and produce a crop. I think of AppHarvest, a large operation in Kentucky growing greenhouse vegetables that is listed on the stock exchanges. We talked about the large glass houses, and agreed these are primarily Dutch operations and can be very sophisticated in both construction and operation of the growing system. We ended our conversation with thoughts on urban/vertical farming indoors in repurposed industrial buildings and agreed that the time will come when this is more commonplace as the technology and economics line up and become more favorable.

Related to this subject, I recently learned of the passing of Dr. Lou Albright, whose career at Cornell started in 1974. He specialized in environmental control and energy management in agricultural buildings, primarily greenhouses, and was the director of the Controlled Environmental Agriculture program. He retired in 2010 but continued to be interested in farming on top of skyscrapers and inside abandoned warehouses – the vertical farming movement. He was another pioneer like Ray Sheldrake who had a major impact on the greenhouse industry.

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