Can you describe the performance that you are unhappy with?

Like other perennials, mine did not grow a lot the first year or two, but have since taken off big time. The first year maybe got 3 to 5 feet, the next maybe 6 to 8, now I get 8 to 10 and would probably get more if I fertilized more often.

They like lots of sun, need lots of fertilizer and water to grow big.

The leaves tend to shred badly in the wind, which I find really ugly, so an area away from wind is a bonus in that regard.

Poor performance - They wilted worse than any banana I have ever seen, on a daily basis during July and August, into September. Occasionally, leaves would hang limp and then die off. They never even reached 3 ft and was half that size when planted in May. Was very slow in leaf production. These got the same water and fertilizing schedule as my other bananas in the same spot. I didn't have any problem with leaf shred because of the protected location. As I mentioned, dead air.

Some of the pups seem to be just like mother. Two of them are barely showing out of the ground, and have been that way for weeks.

It could certainly be the heat. What we've seen with ours, is that on really hot, sunny days, the leaves would wilt as well. During these periods, we give them LOTS of water.. I mean LOTS-O-WAHTAH! We even spray the leaves with the cool water in a non-harsh mist kinda manner (spary). They seem to respond by coming out of wilt during those times.

Also, what kind of soil is in that area? Well draining? Too dry? Too wet?

As mentioned, the DO LIKE lots of ferts too. Most of ours, however, are in pots, so we do have a bit more control. But even in the pots, they are growing like crazy and have for the last 3 years.

Last summer, we did plant one of the pups in the ground as an over-winter test.

This one has just come up a bit over 2 weeks ago. Now, in just a short time, it's over 12" tall! BUT, it's in an area where it gets morning and early afternoon sun. It is shaded from hot afternoon sun (at least until it grows tall and then gets the sun that way).

So, in your case, it could be just too hot, no circulation, which they seem to like and maybe more water and spray their leaves daily or a couple of times daily where possible. (auto sprinkler? 5 mins, couple times a day?)

It sounds to me like you're growing them WAY too dry. When the leaves go limp and then crease along the stalk and then hang down like you said, they are growing too dry. Put a soaker hose between and around them and give the poor things some water. Preferably at night, so they can soak it up and get really hydrated.
Don't worry a bit if they wilt down a little bit in the heat of the day if you know they are well watered, it's a long way to move water from the roots to the top and sometimes they just can't keep up. If they are still wilted in the morning, they need water asap. That is their built-in water sensor unit.... You don't even have to go out there, you can see across the yard if they need water. You can't hardly get it too hot for a banana. But too dry is another story. And if you're not going to water them, then don't fertilize them too heavily either. Because in a "concentrated environment" like that, you actually can burn them with fertilizer. If you water them, you would want to fertilize them then. They can take any kind of fertilizer, and with adequate watering you can give them about twice the recommended amount and really get them cranking up some new growth!Put your soaker hose under mulch if you really want to water them without wasting water. But I'd recommend at least an hour of soaker hose water a couple times a week if you really want to see some growth, and it's not rained.
I think you'll be MUCH more pleased with their performance if you try the above :)
Sandy @ Northern Tropics