Inhibition of seed germination and seedling development was observed in root media in which Kalanchoe daigremontiana either had grown or were still growing. Extracts from Kalanchoe shoots were also effective in inducing allelopathic responses. Examples of plants which were affected include Digitaria sanguinales, Panicum miliaceum, Setaria italica, Trifolium incarnatum, Lactuca sativa, Allium cepa, and Chrysanthemum hortum. Those unaffected included Zea mays, Triticum aestivum, and Avena sativa. Clones of Zygocactus truncatus and Nephrolepis exaltata elegantissima showed a reduced rate of growth when grown in the same pot with Kalanchoe.