Hello. My corn plant is 15 yrs old but i’ve never saw this coming :( is my corn plant dying?I’m really not an expert with plants but I love them. One of the stem is turning brown/black from the main trunk... i do think i might have water her too much? Its winter and temp is low- mid 60’s ferhern. Or is it normal? I’ve also sprinkled some of anti-gnat control...? Can i save it by cutting where the green stem is still alive and restart the new tree from it? Maybe only the main trunk is rotted? Ahhhh I’m just soooo sad its happening- she’s almost 15years old and was doing well... Thank u for sharing your expert thoughts!