Jeff zone 8 N.C.

I know this will sound simplistic but it works for me. I am not an expert so some may disagree but that is ok. I will learn too. Most bananas like a rich well drained soil with even moisture. Too soggy soil can rot them. There are some variegated ones, as well as others, that are more sensitive to too much water. If bananas are in strong sun they may sometimes fold their two leaf halves down away from the sun. If the soil is not already wet, this may mean they need water. If watering them corrects this then they needed more. If it does not then you may have problems with rot or other root issues. Some bananas have more upright leaves and others have more drooping lower leaves. If a particular banana variety you have, usually has more upright leaves but is showing the length of the leaves droop down towards the ground then they definitely need water. After you start noticing this watering will be easy as you will soon determine the correct amount. The goal will be to not let the leaves droop over their length. As they grow and get bigger you will need to add more water. As weather cools they need less.