Dwarf bananas grow between 4 and 8 feet tall, while taller varieties grow 10 to 15 feet high. The plant grows outdoors and indoors in containers to provide a tropical touch to the setting. Sensitive to cold climates, the tropical plants thrive in areas with temperatures above 55 degrees Fahrenheit.eed outdoor dwarf banana plant 2 lb. of an 8-10-8 fertilizer every month during the summer. Spread the fertilizer in a circle around the plant, 3 to 4 feet away from the trunk to prevent direct contact. Fertilize container-grown bananas with half the amount of fertilizer.