Tropical banana trees (Musa spp.) turn any backyard into a tropical oasis, with their oversized foliage, attractive flower clusters and bunches of fruit. Suited to USDA Hardiness Zones 8 to 11, the banana tree benefits from flower pruning, to promote fruit development. The exact time frame of flower pruning varies by the growth habits of your particular tree.
Before your banana plant can develop bunches of fruit, it must first flower. Banana flowers are quite small, but cluster individually off a single stalk and are hidden underneath purple flower bracts. The bracts fall off naturally to expose the flowers, where the bananas will develop slowly. The flowers are necessary to the fruit development, but once you have budding bananas, you don't need them any longer.
While banana flowers will naturally fall off the stalk as the fruit develops, stubborn flowers will remain. Once you notice all of the bananas in the bunch have started to develop -- you will see large clumps of bananas developing from the stalk from top to bottom -- you may cut off the mahogany flower cluster with your knife or clippers.
The longer the flowers stay on the plant, the less energy your banana tree will have to put toward the fruit. Removing the flowers allows the plant to concentrate maximum energy toward fruit development because it does not have to also develop flowers. When your fruit ripens, you remove that, too, and the cycle begins again.
A banana plant will develop its flower 10 to 15 months after the shoot develops, so long as the weather remains warm enough. A light frost can kill banana leaves and temperatures around 20 F can kill the plant growth back to the ground, killing any developing flowers or fruit also.