Cut flowers, specifically Dutch imports, run into 3.7 billion flowers a year or US$1.4 billion. This is an import cost of US$0.38 per flower. Converting urban roof tops for cut flower Urban Farming help make this a local market. Let us assume hydroponic techniques apply to dutch flowers, like the much sought after tulips. Also, assuming plant density of 4 plants per square meter and a yearly yield of 1 per plant, a 1,000 square meter green house can yield 3,700 to 4,000 plants per year. Thus, 3.7 billion / 3,700 per 1000 square meter yields a requirement of 1,000 sqr km of roof top farms. New York city has an urban area of 8683 sqr km. Thus, 1000 sqr km is just 11.5%.
Thus, converting to roof top urban flower farms can save the US from spending US$1.4 billion a year and redirects this back to the local economy. With wholesale prices of US$1.50 per tulip, 4000 tulips can be sold for US$6,000. Selling them retail on Valentine’s day, in New York City, and the values can really soar.