For a new planning hole, I typically use as much as 50% compost / 50% native soil and have had excellent results. Additionally, I mulch heavily with mounds of compost and manure around the base of the pseudo stem.

Good luck.

Rokal

Where do you get manure in a city?

I actually bought manure at Lowe's Home Improvement store, it was $4.97 for a 50 lb bag.

man, I'm going to try Lowes. I bought a bag of manure and compost from HD here and it was just sticks and twigs.

horse manure been very good for me for the past 2 years with conpost

The real question is, what kind of soil do you have NOW? Bananas aren't terribly picky about soil but will do best in a soil that well-drained and stays neither too wet nor too dry, and has lots of organic matter in it. Probably the worst is soil that is sandy and/or low in nutrients.

I wouldn't recommend trying them in 100% compost but I can't think of any soil--sand, clay, or anything in between--where bananas wouldn't benefit from the addition of lots of organic matter. Maybe a peat bog, but I suspect that's not what you have in Texas!

Aside from soil, what bananas need to grow big and fast are lots of sun, lots of water (but NOT waterlogged soil!) and lots of fertilizer, especially nitrogen and potassium.

The only suggestion I have to add is use lots of MILORGANITE found at Lowes or HD in the grass fertilizer section. It is a 5-2-0 NPK slow release natural fertilizer that bananas go bananas for. Using Miracle Gro once a week will help too since bananas are heavy feeders and won't mind the extra nutrition one bit. The rewards are huge bananas that seem happy. Literally pile on the MILORGANITE too since it is virtually impossible to burn plants with.

I use 50% compost and a fifty fifty mix of sand and rich black topsoil.Arenal Volcano has blessed us with 10 foot deep dirt.
I feed 10 30 10 Every three months and a foliar of magnesium, potassium, and 20 20 20 about once a month.