Is the yellow leaf the lowest leaf on the plant. If so, then that is normal since the oldest leaves on a banana will die to be replaced by new leaves coming out of the center of the pseudostem. You don't say where you live. It would be helpful to know so that you get the correct growing advice. In general, bananas like lots of sun, water and fertilizer. They will grow in pots but will not be as happy as in the ground. They are fast growers so given the big three of sun, water and fert., you might see 6 to 8 feet of growth in a summer. Best growing conditions temperature wise are in the 80's with high humidity. Most bananas will cease showing any significant growth below 50.

Steve

The yellow leaf is actually the youngest. the next youngest is a bit more green, then the older ones are all green. It has about 8-10 leaves total.

I live in southern PA.

What kind of fertilizer should I use, and when should I repot and with what?

I have used a banana fertilizer offered by Stokes Tropicals, an internet nursery in New Iberia, LA for years. It's a 6-2-12 ratio with minors. Works with container plants as well as in situ plants. I container grow a few and use Miracle Gro potting mix. I also use composted chicken manure on all of my bananas in the ground. A little goes a long way on the manure in container plants. Look at www.bananas.org. You'll find an answer to every question you have.

Steve

Steve