Bananas are unique tropical fruits that grow in an equally unique process. Because their plants don't adhere to seasonal growing restrictions, bananas can grow year-round with the right conditions, which include heat, light and plenty of water. When those conditions are ignored, banana plants and their roots fall prey to root rot and death.
Bananas grow from corms, or rhizomes, planted deeply in the soil. These corms are hardy down to 28 degrees Fahrenheit for limited periods of time, and may produce many generations of bananas as long as they receive the right protection.
A banana grows continuously, regardless of season, as long as its needs are met. A banana corm puts up a long shoot, which grows for 9 to 12 months, bears fruit and then dies. The corm then puts up another shoot, which goes through the same process. The only way to kill a banana plant is through damage to the corm, which is sensitive to both cold and moisture. Because bananas are year-round plants, they often become subject to inadequate growing conditions.
According to California Rare Fruit Growers, Inc., root rot is the biggest killer of bananas. Root rot occurs when a banana's soil becomes too cold or wet, and causes the corm to rot away and die.
Bananas may stop growing at temperatures under 40 to 50 degrees Fahrenheit, and cease to require as much water during that time. Restrict waterings in lower temperatures and wrap the banana plant to keep the soil dry and warm and prevent root rot.
Always plant and maintain banana corms in the right situations to avoid root rot. Bananas require quick-draining soil and sites that get complete drainage, with consistent waterings and temperatures between 70 and 80 degrees Fahrenheit. Colder weather halts the growth of the plants and may leave the corm vulnerable.