ARS | Publication request: Energy-Efficient Scheduling of Bedding Plants

Submitted to: Greenhouse Grower Magazine
Publication Type: Trade Journal
Publication Acceptance Date: March 26, 2009
Publication Date: April 1, 2009
Repository URL: http://hdl.handle.net/10113/36607
Citation: Runkle, E., Frantz, J., Blanchard, M. 2009. Energy-Efficient Scheduling of Bedding Plants. Greenhouse Grower Magazine. 27:40-44

Technical Abstract: Desirable scheduling of garden plants includes producing a marketable crop for a specific date with the least amount of inputs as possible. A large contribution to input costs for greenhouse production are overhead expenses, and during winter and early spring production, heating can be a large component of overhead costs. As a result, some growers have lowered their growing temperature in an attempt to save on fuel costs. When greenhouse temperature is lowered, plants develop more slowly, and so production time increases. Using the free USDA-ARS software Virtual Grower, we can estimate the cost to heat a greenhouse given the temperature, cropping time, and greenhouse characteristics. Using Virtual Grower and crop timing information with petunia we can identify the date that plugs need to be transplanted for two different finish dates: April 1 and May 15. Then we can use Virtual Grower to estimate the energy cost for heating a greenhouse given the different crop schedules. We calculated this cost for a variety of locations throughout the United States. Except for the two locations in California, less energy was consumed by growing the crop warm (68 °F) compared to growing it 10 °F cooler because of the substantial increase in production time. Thus, an earlier transplant date is required for a cooler production temperature, and greenhouse heating costs are (in many locations) higher earlier in the year. This article is the first in a series to introduce growers to using Virtual Grower in scheduling crops for energy efficient crop production.