Purdue University researchers’ success in using red and blue LEDs as the only source of light to grow ornamental plant seedlings indoors has led to a new phase of determining whether they can reduce production time with more colors. The research is important because most seedlings are grown in greenhouses in the late winter and early spring, a time when sunlight with enough growing power is low, especially in northern states. Seedlings need to grow at that time to meet spring and summer sales of bedding plants, so supplemental lighting from electric lamps is typically needed. The research shows that sole-source LED lighting could be used to grow ornamental plant seedlings indoors with a technique known as multilayer production, in which plants are stacked on top of each other on shelves such as in a warehouse where there is no sunlight. Some companies, especially in Japan, already use multilayer production for leafy vegetables.
This article appears in the January 2015 issue of Acres U.S.A.