My grandpa overwatered a Pothos I really like for seven months, how do I save her?

I am no expert here, but when I was single I had a pothos that I kept forgetting about until it looked completely dead. I would always figure that was the end of it, but I'd go back to watering like normal and it always came back. I named it Lazarus (the guy in the bible that Jesus brings back from the dead).

I won't say it was the best looking plant after that treatment, but it did live. I'd let it dry to the point where you'd normally water it, then go back to normal if it survives. Good luck!

I just got her back, she was in a pool of water, the leaves are yellow and partly black, and I don't know what to do. I would just chop something off to propagate but the stem is yellow as well, are my chances better if I just don't water for a couple of weeks until the soil is dry?

I'm good with plants but far from an expert. If I found that, I would go to my friends place, take a few new cuttings from them, propagate them and and say goodbye to this sad fellow.

But that's not your question. If the problem is really root rot, it's tough. Cutting it and regrowing new roots in water is what I would do.

I would guess that you have root rot, I would get it out of that container ASAP to check the roots and let the soil dry out. White and/or stiff roots are good, soft and brown are bad. Rotting roots can kill the plant so you want to remove them. You want to use isopropanol to clean any scissors or tools used cut out bad roots to prevent spreading any of the stuff causing the rot any where else.

It looks like it may have travelled up to the middle leaf, if the leaf doesn't dry out and continues to spread toward the stem, cut off the yellowing/brown part or even the whole leaf with clean scissors.

The darker nubs on the stem are actually roots, so you can propagate from those if you need to. Just cut the stem an inch or so below some of them, let the cut dry a little bit (5-10 minutes), and put it in clean water for a few weeks. Make sure to change the water occasionally.

Pothos are pretty hardy plants, so you don't really need to rush while working through the roots. I would not put it back in that soil if you find you have a lot of rotting roots. It would be fine for a healthy plant, but yours needs some love (e.g. ignore it once you've dealt with the bad parts). If you don't have any potting soil, you'll have plenty of time to get some if you've already started.