Commercial greenhouse operators raise CO2 levels to 1200 ppm, three times atmospheric levels. (drtimball.com)
Along with the H. J. Heinz Company factory, Leamington has developed a thriving number greenhouses, and now has the largest number of commercial greenhouses in of North America. (mortgagebrokerstore.com)
>> Mastronardi pioneered the first commercial greenhouse in North America, and is a leader in the segment today. (nxtbook.com)