harveyc

John, are the damaged plants more exposed to the clear sky? I looks that way from the photos. If so, heat radiates from that area more easily.

Putting an overhead cover can help protect the bananas even without a heat supplement.

For what it's worth, bare ground can trap heat and release it more slowly than soil with grass, leaves, etc.

More power to you, in-ground bananas in zone 7!

__________________
Reminder to self - Try doing something today that Tog would have done.