proletariatcsp

Hi, nice little musa! Outside is probably best because bananas thrive in full sun, and most tolerate periodic shade throughout the day, i.e., 30% max. A south facing window is optimal if you will continue growing indoors to avoid pests, but outdoors you will need to use insecticidal soap.

There are a few soaps that do not have harmful chemicals like neem, but I don't recommend anything particularly because I use only dish soap, which by itself is not very effective. I agree with the others, however. Your problem was likely due to soggy roots, and the gnats simply enhanced your problems.

Be careful what type of sand you use, I have heard others suggest sand too but unless the sand is dry and deep it will only deter the flies, not irradicate their infestation. Most sand contains way too much salt, and even playground sand may contain enough to harm the plant, so, you will need to leech it very well.

As an alternative to the sand, I would place a piece of window/door screen in your pot. Terra-cotta is a good choice, but the clay will absorb water and you will have to water more frequently. Put the screen in the bottom, and fill about 2-3" (depending on the size of your pot) with pebbles mixed with some soil and the kind of moss used for Orchids, like 50/50. Than fill the rest of your pot will soil and plant the banana so that the upper roots are about 1/2" below the soil. (You may need to put it slightly lower since the soil will compact when you water it in. The screen will keep the pebbles from falling out and the moss will hold enough water so the roots dont get too dry.

If you replant to a new pot, nurseries recommend the new pot is no more than 2" wider than the root-ball. I have repotted many plants from 1gal. into 5 or 7 gal, and they were quickly overwhelmed by mildew, mushrooms, pests, you name it---I've probably grown it by accident.

Good luck.

Chris in FL.