PROBLEM TO BE SOLVED: To provide a gravel culture method solving the problem that conventional gravel culture employs ordinary gravel such as andesite and/or granite, the gravel itself only supports the roots of a grown plant and has little water absorption or root-adherent property, and that water is intermittently given, and therefore the plant runs dry when water supply gets scarce.SOLUTION: The gravel culture method comprises: planting a plant to be cultivated or sowing seeds of the plant in something charged with a porous granulated burnt product produced by granulating tuffaceous sandstone powder and burning the granulated one, into an unglazed flower pot or a container burnt using the tuffaceous sandstone powder； soaking the plant together with the flower pot or the container in a water tank in which water is shallowly filled； and cultivating the plant by mixing solid fertilizer with the porous granulated burnt product or adding liquid fertilizer to water for fertilizer application. The porous granulated burnt product made of tuffaceous sandstone powder has good absorption to naturally absorb water, so that the water is gradually supplied to the plant.【課題】従来の礫耕栽培は、安山岩等の花崗岩などの通常の礫が用いられており、これら礫自体は大きくなった植物の根を支えるだけであり、吸水性や根の付着性は殆どないものであり、水は間欠的に与えられるのみであり、水の供給が途絶えると植物は枯れてしまう。【課題を解決するための手段】素焼きの植木鉢や来待石粉体を用いて焼成した容器に、来待石粉体を造粒して焼成した多孔質造粒焼成品を入れたものに栽培植物を植え或いは種まきし、植木鉢或いは容器ごと水を浅く張った水槽に漬け、肥料は固形肥料を多孔質造粒焼成品に混ぜるか、液肥を水に混入することにより栽培を行う。来待石粉体の多孔質造粒焼成品は吸水性が良く自然に吸水して植物に徐々に水を給与する。【選択図】図６
