To prune a banana tree, allow the stalk to produce fruit until it is ripe. The ideal moment to harvest bananas is when they turn light green. Cut the fruit with a sharp knife, and remove the stalk from the plant by cutting it at the base. Remove unnecessary stems from the plant, clear out unwanted growths, and remove leaves that come in contact with the fruit cluster.
A banana stalk produces fruit once. Remove it from the plant to allow a new stalk to grow. Cut the removed stalk in small pieces, and use it as mulch. Keep a fully grown stem, a half-grown stem and a baby stem. Remove other stems with a sharp knife. Remove leaves rubbing against the fruit cluster, which allows the sun to aid the ripening process.
To remove dead leaves, cut the leaf stalk with a sharp knife between 1/2 and 1 inch from the trunk. Use sharp shears to cut broken leaves at the break point.
Banana sap stains fabric, so wear old clothes when pruning a banana plant. Always sanitize tools after pruning the plant. Use a solution of 3-parts water and 1-part bleach to soak the tools for five minutes, then rinse and let them dry.