Does anyone know what could be causing this to happen to my spilt leaf philodendron? It appears on some of my Xanadu as well. I have been diligently treating all of my plants with neem oil and horticultural oil, alternately, as I have had a big outbreak in mealy bugs, even though I haven’t seen evidence of those on these plants. The younger leaves have been turning very yellow and dying off, though I haven’t seen that in the last week or so after sprinkling diatomaceous earth around the base. Do I have a pest/nourishment combination situation here? Any help is greatly appreciated.



