Abstract: A cell comprising one or more stands in which crop containers are arranged in a plurality of layers one above the other and light sources are arranged between the containers, whereby between a light source (or light sources) and a container located above said light source(s) there is arranged a plate of insulating material, at least the side of the plate facing light source(s) being reflecting.

Abstract: Cases for propagating plants are positionable on supports adjacent a rotating vertical column. Light sources on the vertical column rotate over the plants in the propagating cases so as to provide even illumination. The vertical column is hollow and includes a blower for withdrawing heated air from adjacent the propagating cases. The support structures on which the propagating cases are positioned have rows of holes through which rollers can extend. The rollers are mounted on tracks which can be tilted so that the cases will roll by gravity either toward or away from the column for installing or removing the propagating cases. The light sources are removable from the column and can be selectively removed for varying the distance between the propagating cases and the plants as the plants grow.