Plug Culture for Greenhouse and Indoor Growers
More than a decade ago, horticultural researchers began revolutionary studies to find new systems for rapid mass-production of seedlings. Plug technology evolved out of that original research in the late 1970s and early 1980s. Plugs are seedlings grown in a fine-textured artificial soil mix in special plastic trays containing numerous small “cells.” At the end of a plug cycle, the seedlings possess a relatively tight root mass in the shape of an inverted cone or pyramid.
A single plug tray can hold as many as 128 to 800 seedlings. The cost of soil mix is low because none is wasted in the compact cells. Fertilization is done with water-soluble plant foods, and seedling growth is controlled by environmental manipulation.
Transplantation shock is almost nonexistent. Plug-root masses are stable even with extra-sensitive seedlings, and the plugs are easy to transplant into containers for growing on. One of the most important advantages of plug culture is the speed with which a crop can be brought to a marketable or usable size.
