Question: I have a small, free-standing greenhouse which I plan to heat this winter. I would like to use a propane heater, but I have heard that man-made gases will kill plants. Do I have to use natural gas?

Answer: Many greenhouses are heated successfully with propane. I believe the gas damage you are thinking of occurs when there is a gas leak so be sure your equipment is in good working order. Also be sure to follow any appropriate ventilation requirements.