I discovered several new leaves sprouting on my Gardenia, but I also noticed that it appears to have some sort of coating. I touched it and it felt gritty. Before the new growth appeared, I was having other issues with it. For instance, I found several leaves with pinhead size brown dots on the underside, which I washed off. I've been spraying it to control what I thought was spider mites. But now I have this issue. Is there anything I can do to control these issues? The plant was outside in the summer, but I think I'll just leave it indoors.