Although I have no experience growing 'Montbeliardii', I know from experience that 'Maurelii' can be grown to look like 'Montbeliardii' by treating it with the plant hormone, gibberellic acid.

I took this in 1974 when my father and I were on a road trip to Pennsylvania. For my father, the only goal of this trip was to buy apple pies at an Amish farmer's market. As you see him here, he was eager to leave and buy pies. Little did my father, who died in 1976, suspect that he was being immortalized.

With regard to 'Maurelii' and gibberellic acid, at what stage would you treat the plant? Thanks.

The stage doesn't matter. GA increases the length of the petioles comprising the pseudostem and the length of the leaves, but it only influences new growth. You want to apply treatment gradually and continuously so you don't suddenly get one new leaf bolting high above the others because, without the support of the surrounding petioles, the wind will easily blow it over. The easiest way to apply GA to a banana plant is to pour about an ounce of solution into the opening at the top of a leaf furl that is just beginning to open. GA is quickly translocated within the plant. It will take effect in about one week after application. Reapplication should be made at intervals less than one month. I am sorry, but I don't remember the proper concentration, but a good starting point for trial and error work would be 50 ppm.