In the presence of light, the germination rates of spores of Nephrolepis exaltata, Phlebodium aureum and Cibotium glaucum on three different soils were similar to those on water or water agar. All the soils tested promoted elongation of rhizoids of N. exaltata and stimulated growth of protonemata of C. glaucum. Spores of the fungus Botryodiplodia theobromae germinated completely on water or water agar under light or in darkness but failed to germinate on soils under the same conditions. The results suggest that spores of ferns are not sensitive to microbiostasis of soil. Contrary to microorganisms, insensitivity of spores to soil microbiostasis could be beneficial to ferns because it would be advantageous to their successful colonization of suitable habitats.