Growth Responses of Mentha spp. to Varying LED Light Intensities in Indoor Greening Applications

Indoor greening using edible aromatic herbs such as mint provides aesthetic, therapeutic, and environmental benefits; however, knowledge about appropriate lighting conditions remains limited. This study evaluated the growth responses of three mint species ( Mentha canadensis var. piperascens , M. × piperita , and M. spicata ) under varying photosynthetic photon flux densities (PPFD: 20, 100, 150, 200, and 250 µmol·m −2 ·s −1 ) provided by LED lights. On the basis of trends in dry shoot weight and soil plant analysis development values, PPFD levels around 150 to 200 µmol·m −2 ·s −1 appeared suitable for cultivating Mentha spp., although no statistically significant differences occurred among some PPFD levels within species. Photoinhibition at 250 µmol·m −2 ·s −1 resulted in decreased photosynthetic efficiency and chlorosis, and stem elongation occurred at 20 µmol·m −2 ·s −1 due to light deficiency. These findings contribute to understanding species-specific responses of mint to indoor LED lighting, to inform suitable light level choices for indoor greening.