P Selloum (Philodendron) with little brown spots on some leaves
I have a 30+ year-old P Selloum philodendron that has little tiny round brown spots on some of the leaves. I don't see any evidence of bugs, and some leaves are totally fine. Is this anything I should be concerned about? It was outside last summer and then I brought it back into the house in October. I also took the whole thing out of the pot last summer, washed off the roots, and split the plant into 3 plants (one large, 2 small). It's growing like crazy (it takes up the same amount of space as my baby grand piano!) and appears healthy, but I am concerned because I had a recent whitefly infestation in my hibiscus plants (which were segregated on a different floor of the house). Any thoughts on what these brown spots might be?
Thank you so much! This plant was given to me by one of my college professors 20 years ago, and he had it for a long time before then, so it means a lot to me!
Kat in CT