PROBLEM TO BE SOLVED: To provide a radiocaesium migration inhibitor for plants which can inhibit radiocaesium migration into plants to safely cultivate plants which can be eaten when plants are cultivated in soil containing radiocaesium, and to provide a method for growing plants.SOLUTION: The invention relates to a radiocaesium migration inhibitor for plants, the radiocaesium containing a solid content containing iron hydroxide and sulphate. An aspect in which the iron hydroxide is Fe(OH), an aspect in which the sulphate is at least one kind selected from CaSO, KSO, NaSO, and MgSO, an aspect in which the solid content contains CaO further, and an aspect in which the solid content contains SiOfurther, and the like are preferable.
