Oysters are produced in each district in Japan, and Hiroshima Prefecture is especially famous as a high producing district. Accordingly, the production of oysters has created oyster shells as a by-product. Oyster shell porous concrete (OyPoC) is porous concrete using crushed oyster shells as aggregates. In previous researches, it was found that OyPoC with finely crushed oyster shell had high plant-growing performance. However, all of the planting test periods were less than three months; the long-term plant-growing performance of OyPoC had not been clear. In this study, the plant- growing performance of OyPoC was investigated by conducting long-term planting tests over one year. OyPoC and hybrid porous concrete (HyPoC), which was combined with OyPoC and crushed stone porous concrete, were prepared for the planting tests. From the test results, the plant-growing performance of OyPoC was higher than that of HyPoC because OyPoC had much higher oyster shell aggregate than HyPoC. In contrast, there was a risk of the severe summer drought withering the grass on OyPoC and the watering in the summer was found to be important.