I distinctly remember watching a movie on tv as a kid. I posted on the Lost Media reddit, but unidentified media seems more to the point. There was a bunch of people living in a greenhouse so they either were vegetables turning into humans, or humans turning into vegetables.
They may or may not have been transformed with a liquid or an experiment that went bad.
It was ending with a flood and it may have been part of a series since the ending seemed inconclusive.
The overall tone was very european, it may have been french or scandinavian. It had a Moomin feel and aesthetic to it, but I researched that option and couldn’t find anything satisfactory.