Question: I have aglaonemas in my greenhouse, but they look bad every winter. They are wilted looking, and many of their leaves turn yellow.

Answer: That’s almost assuredly chilling damage. Where some tropical plants survive clear down to the freezing point, aglaonemas go downhill anytime temperatures are below 50 degrees for a prolonged period. Move them to the warmest part of your greenhouse, or bring them indoors with you during the winters.