Bananas.org - Red Ensete-Drainage Question

i have seen ensetes grown to huge sizes in pots at local nurseries over the year so this past spring when i saw a large one (5 ft) for sale for $25 at a local agway i bought it. i planted it in a 3 ft wide and high pot. i sealed the drainage holes and put a thick layer of rocks on the bottom so the pot wouldnt blow over. i thought the pot was big enough so the banana wouldnt be sitting directly in the water but i figured by filling the drainage holes the banana would have an abundance of water and grow huge leaves. i have done this before with hibiscus acetosella. ( i saw it grown in a pot sitting directly in a fish pool at a local nursery-1 or 2 inches of pot in the water) With the red hibiscus grown like that it grew very quickly and i kept trimming and trimming and it just got bushier and bigger and couldnt get enough water. well the same cant be said for the ensete. it seemed stunted-never grew much taller and the leaves were 3 ft long tops-they never got bigger-was hoping for them to be really big. at first i thought it was just waiting for the heat to kick in but now i am thinking maybe it was the drainage or maybe it was limited by the pot size? seemed like a big enough pot to me. Few weeks ago we had a storm with 50 mile an hour winds. when i got home the ensete was at an angle so i straightened it up and then went to bed. next morning it was ripped clean out of the pot-ripped the stem at the base right off the roots. was really weird. thinking maybe my too soggy pot made for soggy rotted roots? or can the wind do that? all moot for that poor banana but would love any info cuz lord knows i will try again next year. (i cant not buy an affordable banana plant! 2 years back when the local stop and shop got 20 musa zebrinas in it was all i could do not to fill my whole yard with them) would appreciate any insight or info-thanks very much-David