Just a little something to share, I happened upon 100 seeds from our temple in S.Korea ( Jogyesa in Seoul) of various lotus seeds. The lotuses these came from were from various youth groups, schools and Buddhist (denominational) Universities across the region during buddha's Birthday in 2019 (May.12th) This is the second growth year for my lotus plant and it should flower within the next several weeks. In terms of hardiness, lotus (Nelumbo nucifera) is a pretty strong plant but does require heat to get going. I find lotus enjoy a water temperature anywhere from ~19-34c. Best growth has been around 25-28c I did not protect this plant last winter at all. I let it produce tubers in early November/December outside. Overprotecting/overwintering lotuses in a garage or other location I have found encourages them to rot. Currently, it is growing in a black poly 110Gal water tank for livestock.
