Propagating Frames Small 320×177 Medium 640×353 Large 1024×565 Download Tiff Original 2400×1325 | (1.2 MB) Description Illustrated is a permanent propagating frame in a greenhouse. Keywords greenhouse, permanent propagating frame, propagating frame Galleries Greenhouses and Cold Frames Source: L. H. Bailey Standard Cyclopedia of Horticulture (New York, New York: The MacMillan Company, 1917)