I have a philodendron ‘xanadu’ that’s developed a 3-4 ft aerial root. Should I cut it off or just let it go? If cut off, where?

Answer 1

You can cut them off if you don't like the looks. Cut them off at the base right above the collar. The collar will heal leaving a node.

https://www.gardeningknowhow.com/houseplants/hpgen/aerial-root-information.htm
https://www.gardeningknowhow.com/garden-how-to/info/trimming-air-roots-plants.htm
https://www.gardeningknowhow.com/houseplants/philodendron/xanadu-philodendron-care.htm