I recently had to discard a lovely streptocarpus, Tie-Dyed, one of my favorites, because it got some strange disease on it. At least, I assume it was a disease. One of the leaves developed a large, dry, tannish area in the middle of the leaf. It didn't get bigger, but other leaves developed it, too. Yet, the plant continued to bloom happily. Whatever it was, was confined only to that one plant; none of my other steps developed it. The area was thick and dry, not thin or water-soaked, as in Botrytis. I tried spraying it several times with Physan20, but it didn't help. Being in a plastic bag for awhile didn't help, either.

The plant was growing under a two-tiered, two foot wide light garden, 10 inches below the 2-foot long grow light bulbs. I grew it in Miracle Mix, which has fertilizer already in it and lasts a year, and left the light on for 10 hours. Our heater has a humidifier attached to it, keeping the house and grow room at around 50-60 % humidity. However, the room did get down to 60-62 deg. at night, in the winter and 65 or so in the daytime. But the other streps growing next to it did just fine.

The leaves finally all died, except for a couple of tiny, tiny leaves that were trying to grow at the center. The plant even had a couple of buds still on it, but I pitched it.

Any idea what could have caused the brown spots on the leaves? I'm at a loss to explain it. Thanks.