Tropicals & Tender Perennials: Scary leaves on my new banana, 0 by SleestakJC

SleestakJC wrote:
One week ago I purchased a Musa Zebrina (Blood Banana). It put out a very beautiful happy new leaf after a couple of days. Then yesterday the second leaf fully opened and it looks AWFUL. It has a mottled brown blotch a little larger than a silver dollar toward the bottom and one whole side of the leaf is extremely thin, mottled, fleshy and curled up. The day I bought it, I repotted it in Miracle Gro Moisture control potting mix with a handful of compost mixed in. I've kept it evenly moist and haven't let it dry out. It gets 4 or 5 hours of morning sun and an hour or two later in the day. Am I doing something wrong or is it a pest/disease?