Some of the stalks on my philodendron are turning yellow and getting "gooey." Is this a disease or root rot from over watering?
Certified GKH Gardening Expert
The top inch or so of your soil should dry between waterings.
Make sure the pot has adequate drainage holes so excess water can drain from the soil.
This sounds like overwatering so always check the soil, don't water on a schedule.
If you think the plant has been overwatered, you can life the plant from the soil and check the roots. They should be firm, if the roots are soft and mushy, this is root rot.
You can trim the bad roots away and repot if fresh soil
Philodendron can recover if there is enough healthy roots remaining.