Eslee's Lemon Balm

I was so excited to get this growing, and then something very bad happened. All of the leaves started turning a very dark, chocolate brown around the edges. It was suggested that it was sunburn, but relocating it to a less sunny spot hasn’t seemed to help. The newer leaves also develop the browning. Otherwise the plant seems relatively normal and healthy. I still need to do more research and see what went wrong. I’ve never experienced a problem growing anything in the mint family—usually quite the opposite problem!