if its all organic i dont think you can really over fertilize, it would just go to waste or wash out what it doesnt absorb.

compost and mulch are the only think i give my naners, but they love the weather here

It's really difficult to overfeed a nana. I feed mine chicken manure tea regularly. In a month's time, it grew from 11" to almost 3 feet.

Bananas=FEED ME! I use Milorganite which is processed biosolids that make the bananas go...well Bananas! I have gotten close to 18 feet in a growing season.

i shy away from using milorganite on my fruiting plants, they make mangos taste like sewage (which it technically is)

Hatcher mangos one year tasted like sewage, i would place a large wager they experimented with milorganite.

its a controversial fertilizer, its basically a byproduct of sewage treatment making the companies supply free and their profit margin large, so beware of people trying to sell its merits.

Here is a link that might be useful: http://en.wikipedia.org/wiki/Milorganite

I second mango's post about Milorganite. It is made from industrial sewage from Milwaukee. There is no regulatory control over how many ppms of heavy metals such as lead, cadmium, arsenic etc it contains. Plus, they are not required to disclose or even test for these contaminants. You are potentialy contaminating your soil with these metals for decades, and centuries, plus ingesting these materials by consuming plants grown from that soil. Bad stuff....think worm compost and organic!!!

I don't know if you can over fertilize with 100% organics but you can with commercial fertilizer. I just killed my banana, 8 orange and 5 pawpaw trees with too strong a solution. Set me back 3 years.