I'm in disbelief that no one has knowledge or an opinion, concerning this very popular houseplant, based on her/his own experience. I really do wish to treat my heartleaf philodendron well.

I am not an expert, but my philodendrons, as well as pothos, do not seem to resent staying in their 4" pots for several years. A pot that is too large can tend to stay moist and encourage root rot. If you do decide to repot, it is recommended to use a new pot that is an inch or two bigger than the original one. I often take a plant out of its pot, trim the roots and put it back into its old pot with some new, fresh potting soil. You might want to look for threads that describe Al's 5-1-1-1 recipe for potting soil. I myself use a mixture of one part moisture control potting soil (contains coir) to 2 or 3 parts soil conditioner and 1 part perlite. Soil conditioner is a product sold in the SE which is chunky wood/bark pieces meant for improving garden soil. It's the closest I can find to what Al describes. Good luck!

Suggest you read the thread below yours "New to plant life"

Thank you, junco. That's a useful response.