One morning I went down to check on my plants in a basement grow tent, and I was horrified to find that around 30 percent of the leaves on the H. burmanica growing in the semi-hydro container had turned to gray paper. I was as if someone had burned or dehydrated the leaves. In all of my years of keeping Hoyas, I had never seen anything like it. I had a couple of theories that maybe I had burned the plant with fertilizer, or that the grow tent was too hot for it.