Howdy. I have an Agave americana with what I believe is a watering issue. It is set in soil, in a greenhouse in the middle of Michigan. We keep the greenhouse 79-87 degree range. We do not create artificial growing periods; lights are only on during the day. So the question is, with these conditions, what is causing bottom leaves of the Agave to wrinkle, then turn brown, then black? We water very little, knowing that Agave do not like water when not growing, but even this little might be too much. What do the symptoms look like? If they aren't pronounced enough, I can get a newer photo, with worse problems. But look on the uppe rleft of the photo. You can see some of the dead and dying leaves This happened last winter; over the summer it returned to full health. Now it is happening again. How do I prevent the bad half of the cycle?