A relative got a huge, beautiful philodendron bipinnatifidum from a friend but never liked the plant. At Christmastime, after this warmish winter in Connecticut, I saw the plant had been left out on the deck, all leaves frostbitten, the pot - without drainage - was full of cold water. Emptied water, got it home. No living leaves. Top of the 2" thick stems were soft and had begun to get moldy. Put anti-fungal treatment on which seems to have pretty much stopped the mold. Top 1" or more of stems are soft and yesterday seemed to be supporating with moisture although less so today. Should I saw the whole stem down to a place where it is solid? If so, should I treat the raw cut in any special way? How long should I wait and hope to see signs of life and regrowth before giving up? This was such a grand, exuberant plant, I would love to see it survive and at last get the good treatment it deserves!
Definitely consider cutting off all damaged tissue. As long as the root system is still alive the plant will likely make a comeback. Just for safety, put a little anti-fungal agent on the place where you cut it since the plant is already stressed and will now be prone to further maladies. But I've seen these plants get frost bite before and recover fully. Since you are having to totally begin the plant again now is the time to consider repotting. These plants love fast draining soil. They don't particularly like to stay soggy but do like to stay damp. I'd suggest a soil mixture which you can easily make yourself. Combine equal portions of good potting soil, peat, Perlite, and orchid potting media (bark). Keep it damp. Very likely your plant will come back and out grow the pot! The species is very tough and is commonly used as a yard plant all over southern Florida. Doesn't freeze often, but it does freeze down there!
