The banana plant, often mistaken for a tree due to its size, is botanically classified as the world’s largest herb. Its trunk is not woody but a “pseudostem,” formed by tightly packed leaf sheaths. The fruit itself develops from a flower and is technically a berry, as it originates from a single ovary. These fruits grow upward in tiers called “hands” on a large hanging stalk known as a bunch.
From Flower to Full Size: The Maturation Period
The time it takes for a banana fruit to reach full size and be ready for harvest begins with the emergence of the flower stalk, or “bell,” from the top of the pseudostem. This stage marks the beginning of the fruit development period, which is distinct from the ripening process. The duration from the flower’s appearance until the fruit is plump and mature generally ranges from 75 to 150 days.
During this maturation window, the individual bananas, sometimes called “fingers,” fill out and transition from an angular shape to a more rounded, hard form. The fruit at this point has maximized its starch content, which is the primary measure of maturity for harvest. Short-cycle varieties may be ready closer to 60 days, while others can take up to six months. Once the fruit has reached this firm, full-sized stage, it is considered physiologically mature and ready to be cut from the plant.
Key Environmental Factors Influencing Speed
The wide range in maturation time is heavily influenced by ambient temperature and the specific cultivar being grown. Bananas thrive and develop fastest in tropical conditions with optimum temperatures between 25°C and 30°C. Heat accelerates the metabolic processes within the plant, leading to a quicker turnaround from flowering to a mature fruit.
Cooler climates or seasonal temperature fluctuations dramatically slow down the maturation period. Water availability is also a major factor, as the fast-growing banana requires a constant and full supply of water to support the large leaves and develop a heavy bunch. Different varieties, such as the common Cavendish versus a plantain, have their own inherent growth rates, further contributing to the time variability.
Why Bananas Are Harvested Green
The vast majority of commercially grown bananas are harvested when they are fully mature but still hard and green. This practice is based on the fruit’s biology: the banana is a climacteric fruit, meaning it can ripen successfully after being detached from the parent plant. Harvesting green separates the maturation stage from the later ripening stage.
If bananas ripen fully on the plant, the starch converts into sugar while the peel softens. This causes the fruit to become mushy and the peel to split, making it highly susceptible to damage and spoilage. Ripening on the stalk also leads to uneven maturation across the bunch, making the harvest commercially unviable.
Harvesting green allows the fruit to be transported thousands of miles to market before the softening and sweetening process begins. Once they reach their destination, the green bananas are exposed to a controlled dose of ethylene gas in specialized rooms. Ethylene, a naturally occurring plant hormone, triggers the fruit’s internal ripening mechanism, ensuring a uniform color and texture for consumers. This post-harvest treatment allows for precise control over the ripening timeline, ensuring the bananas arrive at stores at the ideal stage of ripeness.