Well ur gunna have to settle for 20-25' they rarely exceed that outside their native habitat, if you protect the pstem over winter you can get up to its fullest potential for your climate, but wind will play a role too, it seems they don't get much where they come from...
Mines about 18 months old now, if that, been in ground almost 4 months to the day, new rollers top 8' and the pstem is up to about 4.5'
It's got several pups on runners now too, I need to cut them off and extract them and growing like crazy!
Can you get a pic of your wee one?
I think most (all?) of them come from tissue culture and TC plants are known to mutate alot, you may in fact have a Mekong midget, if so... Don't lose it! A hardy dwarf banana that is actually small! Holy crap! That could be a little mine! I'd love to have one! More likely your plant is experiencing some sort of problem that has set it back dramatically, if so your tactic of continuing to care for it is your best bet, and next year it will take off, but it's hard to say...a pic might help...

Here's mine. As you can see, it looks healthy, has a beautiful color, ts just small. Actually, at this size you would never know it was a banana.

I do have experience with them, growing them for the past 3 summers. Mine are perennials here in Michigan and do come back in the spring from being killed back to the ground.

Do you have yours growing in any shade? My understanding, and my personal experience, is that they actually prefer shade unlike other bananas. Mine only get 1-2 hours of direct sun a day.

This one is pretty much in full sun, unless you count the shade of the white picket fence around it. The fact that they like shade is good to know. Eventually I would like to move them to a location that will get partial shade, but I need to add an addition to the house first.

How tall do they get in Michigan? I would have a much longer growing season down here on the Mississippi gulf coast.

btw, I planted this one just in the mucky clay soil. Pre-Katrina, I think there may have been a shed there. I did not do a soil test, but that might be why it is doing so porley. I'm going to just keep fertilizing it and hope it takes off.

When I add the addition to the house, I would love to dig a hole with the back-hoe and fill it with a truck load of manure and transplant them there.

I would definitely amend the soil so it's not so dense. If your clay soil is anything like ours here, when it gets hot and dry, the clay almost turns into rock that you can't penetrate.

The tallest I've seen mine get is only 8 feet, not bad considering our frost free months are only May through September, sometimes we don't get a frost until mid-late November if we're lucky.

Since they've been in ground for a couple years now, and 7 feet tall currently, I'm expecting probably 10 feet this year. Yours should be able to easily get to 16 feet or taller.

Never heard they like shade, I'm pretty sure that all bananas want full sun, mine couldn't be in more sun, and has white rock mulch reflecting back at it...

A friend has one that was slightly larger when we put em out this may, his is taller, but hold 3-4 leaves and the trunk girth is half what mine is...he credits mines size to the increased sun mine gets...and marvels at it every time he comes by...

As far as size, only time will tell, 25' is possible given the pstem is up for more than one season, shouldn't be a problem down there, but wind might be, I read they don't like it, but then again mine stands up to wind like a champ!

Honestly after see the pic... I'm very suspicious that what you have there is musa basjoo, the leaves look awful thin, my Mekong makes paddle shaped leaves like a cavendish does, and has a dark trunk, yours is too small to ID for sure...
If it pups several feet away from the mother, it's probably a Mekong, if it pups at mammas base, it's likely basjoo...

I am interested to see pups coming up away from the mother. I have never seen that before. The other (unidentified) plants that I have been growing pup right with the main stalk, as does my ice cream banana that I got at the same time as this one.

I still have a couple of good months of growing season left here. I will keep ya'll updated.

I believe Brian's Botanicals website says they like a little shade. And yes they definitely pup a few feet away from the mother, so if you have one specific location you want your plant, make sure to leave room for it to spread. Mine are popping up in areas I don't even want them. Maybe slightly invasive?

My MG is from a very small plant last fall. It's currently about 15 - 17ft. 2 side sprout came in the original pot and are in the range of 10ft. with the bases close, similar to other bananas. A rhizome shoot came up about 10 ft from the base of the little clump. It quickly grew to 5 ft. This afternoon I dug it and potted in 7gal for the winter. Mine is near the base of a queen palm so it gets mixed light shade.

Potentially slightly invasive I'd say..yes!

Compared to one grown very similarly, and the same age as mine, but given less sun, mines got a much thicker trunk and has and holds more leaves, than its semi shade grown counterpart.

It finally started growing. From early June to Mid-August it only grew about 6". I should have taken notes on when it finally showed progress, but in the last several weeks it has shot up to about 5' tall! This gives me hope that I will have a real giant next year.

trunk of 2 year old

about 9 ft tall

here is what mine looks like now

it will grow give it time..they need lots and lots of food fert them heavy..I use banana fuel but they will use just about anything you can give them