Hammocked Banana

The latest I would transplant is June, but thats just me. If you insist on keeping them out I would transplant them deeper asap, as in this weekend. Alternatively, I suggest that u just keep mounding soil up around them, bit by bit, to avoid transplant shock, and will keep water away from the stem.

If you pot them up they will be much larger next year. What you must understand about bananas, is that the main part of the plant is underground, the corm. The corm is where all of the plants energy comes from, which is why burrying the plant deeper protects it, you are protecting the corm from freezing. Even if the plant were chopped down and was shorter next year, it would still have a larger corm, and so more energy stores, which will result in much faster growth. It is growing slow right now bc your plants have virtually no corm since nurseries buy tissue cultured plants. Your plants are currently focusing on growing roots to feed the corm. As the corm contunues to develop, the growth rate will increase.