Cut all sprouting flower stalks -- except for the first one -- at the base of the plant with a machete. This will keep the stalks from regrowing. The one sprout you saved will develop another stalk.
Trim the fruiting stalk down 30 inches from the ground once it is harvested. Chop the banana stem at the base three weeks after harvest.
Cut any dead flower stalks into chunks to use for mulching for other plants.