I have the same problem here in South Florida. I tried bagging them and putting one each in the bag, a ripening plantain, and a store bought banana... no help.

Then I removed a hand from the tree and did the same thing, no help. I've made note of the size of the hands left on the tree and they continue to get larger in length and diameter so I'm leaving them alone for a while more. If they don't ripen in another month, I'll fry them like plantains :-)

PS, the ones I removed from the tree 5 weeks ago and bagged laid on my counter and did ripen nicely (without the bag) while the ones on the tree stay green and hard.

I was told when we started the banana's in our yard that they do not ripen on the tree, you must cut the stalk and hang inside to ripen. That is the way we have been doing it and it works great. Be aware, if you place the stalk in a plastic bag, all the banana's will ripen at the same time. We found that out the hard way. Hope this is the correct way to ripen them, but works for us.

I just dug up an article from a guy who sounds like he knows just about everything we should know. He shares it at:

http://webebananas.com/culture.html

In short they do ripen on the tree, after ~ 6 months. GREAT reading there.

Bananas do ripen on the plant.They can take anywhere from 3 to 10 months depending on your climate and time of year.You can cut some early from the bunch and place in a paper bag to ripen.If you wait for them to get ripe on the plant they will all get ripe about the same and it would be hard to eat them all before they spoil