The aim of this research is to clarify what the learning environment and teacher's support are to raise 5-year-old children's spirits of inquiry. Two reasons to raise children's spirits of inquiry are the following. First, the section of "Environment" in the Course of Study for Kindergarten (2008) mentions how to raise them. Second, we can use kindergarten yard to foster their spirits of inquiry. Findings of this study reveals six features of the environment and support in terms of children's two interactions with plants: (1) materials to evoke children's interests and spirits of inquiry, (2) environmental arrangements to grow plants with their own hands, (3) a teacher's interactions with children to share their ideas, (4) a his/her interactions with them to make them complete tasks, (5) his/her encouragements to make children have confidence to do their tasks, and (6) his/her interactions with children to make them try them again.