If you slice through a young banana stem, you'll notice little box-like chambers running through it, separated by encasing smooth layers of "skin." This skin becomes what we call banana bark as it matures.
If the weather is very rainy (a likely event in East Maui), I'll throw the bark under my raised porch where they continue to lose the water they're holding. Without the heat of the sun, however, it does take even longer.
On sunny days I can sometimes speed the drying by placing almost-dried bits and pieces in a black plastic bin and leave it in the sun on the porch. If I let the banana bark dry out too much, however, the pieces are often too brittle for me bend and fold. I can moisten them and let them absorb just enough water to make them pliable again. (Basket weavers have the same problem with their material as well, often having to soak dried-out fibers from their stashes so they can be used in the basket-making.)
It is also the reason I don't often use bark that's dried on the tree. Many times the bark is too flaky for my purposes.
Eventually I will have a large stack of materials and I can begin to work on the fiber sculpture pieces.