Dept. of Plant Biology Project Objective Greenhouse production of annual bedding plants comprises a significant segment of the floriculture industry in New Hampshire. However, it is during these months that New England receives its lowest ambient light levels.
Light is a limiting factor in plant growth.
The limited sunlight and shorter daylengths of the winter months can cause plants to grow more slowly and less vigorously. For this reason, growers face the decision of whether or not to provide supplemental lighting in order to increase the photosynthetic rate of these plants. Use of Technology Growers have several lighting types to choose from depending on their intended use. For growers of stock plants, increased photosynthetic rate is most desirable, considering that production is based on the number of vegetative cuttings that can be harvested from a stock plant throughout the growing season. HPS lamps provide a light quality concentrated in the PAR of the light spectrum, therefore, they are a wise choice for stock plant growers.