I planted banana plants (gifted by my neighbor who harvests bananas ever 6 to eight months) in my backyard. They are alive and growing for over 7 years at the rate of about 2 - 4 inches a year for the last 9 years. When I planted it was about 3 ft and now it is about 5 ft. my neighbor is astonished but could not find one good reason for this. He again gave me few more plants to grow in my backyard two years ago and these plants are relatively fast-growing (4 to 6 inches per year). Can someone suggest a reason for the extraordinarily slow growth?
It may depend on where you are. In E TX , zone 8, they grew almost a foot per month ( in summer). Although I had small stalks of small bananas , We never had the 14 months of warm (or not cold), weather it took to ripen them. It was an interesting plant for conversation.It should send up at least two new plants each year as the original tree will die after producing fruit.
I have bananas. Gran Naine (Chiquita). 2-4 inches seems remarkably slow to me for growth. I would check the soil pH first. Like citrus, bananas like 5.5-6.5 of well-draining soil. If it's too wet, or the pH is too high, you won't be able to absorb certain nutrients. If your leaves have purple regions between the veins, your plant is not absorbing phosphorus because of one of the above.
My bananas are nutrient hogs, especially if I don't prune away the babies (but who wants to kill a cute little baby banana plant still attached to its mommy). High potassium food specifically for bananas is readily available.