I believe your plant is indoors? That's ok, provided:
- 8 hours of bright light per day
- temperatures remain above 40 F
- it is not overwatered
For a potted plant, don't check the soil moisture at the top. Instead, check the soil by sticking your finger in a hole at the bottom. If the soil there is wet, it is not time to water.
The banana plant will go "dormant" and loose some or all of its leaves when the day time high temperature stay below 65 F.