Bananas

People have gone ape over bananas for a very long time - but can you grow your own?

The answer is yes, you can! ​

Left to right: plantain, red banana, apple banana, and Cavendish (TimothyPilgrim) CC BY-SA 3.0

Native to Indomalaya and Australia, bananas are believed to have been first domesticated in Papua New Guinea around 6,000 years ago.

Bananas are the world’s largest herbaceous flowering plant. Standard banana plants can reach 45 feet in height, but most end up only 16 feet tall. Dwarf varieties can range from 4 to 12 feet in height. According to Guinness World Records, the largest bunch of bananas held 473 bananas and weighed in at 287 pounds!

The banana plant
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Most people refer to the banana plant as a tree, but it isn’t. Bananas plants are perennial herbs that grow from rhizomes. (If you recall, rhizome are underground stems that grow horizontally and herbs, in this case, are non-woody plants.) The fruit, technically, is a berry. The trunk of a banana plant is a false stem, called a pseudostem, made from tightly wrapped leaf sheaths that grow out of a mat or stool, called a genet, that forms a crown.

Banana crown (Obsidian Soul) Public Domain

Each year, from the genet, new shoots will emerge to replace the parent plant, after its fruiting cycle is complete. The first lateral shoots to come through the soil surface are called peepers. As they grow, they are called suckers. There are two types of suckers: water suckers and sword suckers. Water suckers have broad leaves and a small rhizome base. These do not develop into plants strong enough to support a crop. Sword suckers are just the opposite, with a large rhizome and narrow leaves. Newly emerged leaves that are still rolled up are called cigar leaves and they are very fragile. Once foliage leaves are present, they are called maidens. The sucker selected to replace the parent plant each year after fruiting is called the follower or ratoon.

Banana flowers

From the central growth of leaves, a floral stem or aerial true stem, also called the banana heart, emerges with a cluster of female (pistillate) flower. Each of these female flowers develop a seedless berry by parthenocarpy (fruit development without fertilization). These flowers are arranged into two rows that, ultimately, become a bunch, or hand, of bananas. Before that happens, however, those female flowers become longer and skinnier. Then, the far end of each female flower becomes a male flower! These males may or may not produce fertile pollen. Sometimes, in-between the female and male flowers, a third, hermaphroditic, flower emerges. These neutral flowers do not produce pollen or fruit.

Banana flower (Ruestz) CC BY-SA 3.0

Bananas as food

We are all familiar with the edible fruit of a banana, but, the banana flower is also edible in the same way that an artichoke flower is edible, except that they will stain your hands the way a beet can. Traditionally, the hands are rubbed with oil before handling these flowers. You need to remove the tough outer petals to reveal the tender heart. It is actually the bracts that are eaten. Bracts are modified leaves that surround the base of an individual flower. The outer petals look like giant pink Belgian endive leaves and make attractive food containers. Also, the leaves and petals are often used much like corn husks and grape leaves  are used to wrap other foods for cooking.

Wild banana (Warut Roonguthai) CC BY-SA 3.0

Banana varieties

Modern dessert bananas evolved from two wild seed-producing predecessors: Musa acuminata and Musa balbisiana. There are three major types of domestic banana:

• Musa x troglodytarum - Fe’i bananas, mountain bananas [These are usually boiled.]
• Musa acuminata - Cavendish, the common yellow dessert banana, red bananas
• Musa balbisiana - plantains [These are usually fried or baked.]

From there, a genetic system of cultivar identification has been developed, but we won’t be heading down that rabbit hole. It is enough to know that there are dozens of cultivars, including:

• Musa x paradisiaca - starchy, cooking bananas, green bananas, and plantains
• Musa acuminata x M. balbisiana ‘Silk’ - apple bananas

[Note: there is no botanical distinction between plantains and bananas.]

​Because banana plants grow so quickly and look so nice, some people grow them simply for looks. This means you need to be on the lookout for ornamental varieties when shopping for a banana plant. Ornamental varieties include Ensete ventricosum, Musa ornata, and Musa sikkimensis ‘Red Tiger’. These will never produce fruit.

How to grow a banana plant

Being a tropical plant, bananas prefer heat, humidity, and sun. They generally do not handle wind or compacted soil very well, so be sure to select a site that is sheltered and has good drainage. You can improve a suitable site by digging in some aged compost ahead of time. [I just ordered my own banana plant and will keep you posted on its development.]

Growing bananas in a container

Because banana plants are actually rhizomes, it is easier than you might expect to grow one in a container. You will probably want to grow a dwarf variety. The container needs to be at least 24 inches deep. If you live in USDA Hardiness Zones 9 to 11, you will want to keep your containerized banana in the shade during summer afternoons, and bring it indoors over the winter, while the plant is young.

Harvesting bananas 

Ripe bananas look different to certain animals. Some animals, such as zebra finch and reindeer, are able to see ultraviolet light. When they look at a ripe banana, it glows! If you have one of those handy dandy dollar bill checkers, you can see for yourself: ​

Ripe bananas under normal light (Kate Russell)

Ripe bananas under ultraviolet light (Kate Russell)

Commercially grown bananas are often picked green and shipped in giant plastic bags that have been sprayed with pesticides. Bananas produce a lot of ethylene gas, a ripening agent, when temperatures are warm enough, so they are kept cool to prevent ripening until they are closer to where they will be sold. The yellow color that we are all so familiar with is not exactly natural for the Cavendish banana, which is the primary cultivar found in stores. This particular banana is still green when ripe. Since shoppers prefer the yellow color, these bananas are placed in pressurized ripening rooms, where they are gassed with ethylene and held at specific temperatures to ensure uniform ripening. These high tech procedures and the economies of scale have made life difficult for small scale banana growers. Today, all banana growers are facing a very big threat.

Pests and diseases of bananas

The popular Cavendish banana is facing extinction. Because most bananas are grown using monoculture and a single genome, it is very susceptible to a fusarium fungal disease called Panama disease. Panama disease fungi enter the plant from the soil and start reproducing. This fungal population explosion, in turn, clogs vascular tissue, causing the plant to wilt. This exposes unaffected parts of the plant to so much sunlight that the plant dies. This happened to ‘Gros Michel’ or ‘Big Mike’, the Cavendish predecessor. As early as the 1920s, banana shortages started to occur as a result of this fungal disease. The song, “Yes, We Have No Bananas” actually came out of those shortages! By1960, all ‘Big Mike’ banana plantations were threatened by this disease, so a decision was made to switch over to Cavendish. That worked well enough for the past 50+ years, but the Panama disease fungi has now caught up with Cavendish. Since all Cavendish plants are genetically identical, this could mean the end of the familiar banana. The same thing happened to the potato in 1845 Ireland. Growing large quantities of identical plants is a recipe for vulnerability. If that weren’t enough, there are other fungal diseases that can also infect banana plants, such as black sigatoka. Banana bunchy top is a viral disease that can attacks bananas, along with a bacterial wilt disease.

So, before the banana, as you currently know it, disappears from grocery store shelves, you may want to start growing your own!