Monitor banana plants carefully so the soil remains moist but not wet. Banana plants in open ground require up to 1 1/2 inches of rain per week. In areas that are drier, give additional water.
Place a hose at the base of the banana plant and let it run slowly for several minutes to soak the ground around the deeper roots. This ensures that more than just the top few inches of soil get moist.
Poke your finger an inch or two into the soil surface of container grown banana plants to see if the soil is dry before watering. If it is moist, wait another day or two to water. If it is dry, add water until it runs out the bottom of the pot.