Q.Philodendron plant is wilting
One of my formerly healthy older philodendron plants started wilting and fertilizing and watering did not help. I then transplanted it into new potting soil. It still is not recovering and now another one across the room is starting to wilt as well. What should I do?
Make sure the soil is a good quality commercial potting soil. Check to make sure that the container has adequate drainage holes and that any excess water is draining from the soil.
Droopy leaves are generally an indicator of either too much or not enough water.
The top inch or so of soil should dry between waterings.
Here is a link to refresh you on the care requirements.
https://www.gardeningknowhow.com/houseplants/philodendron/caring-for-philodendrons.htm