Hi!
I bought this string of hearts a few months ago and I've been noticing lots of yellow leaves in the pot. The vines seem to be fine, its grown a lot since I bought it but there is lots of yellow leaves inside the pot. I'm wondering if I'm over or under watering it? It hangs to the right of my south facing window.

Here's a photo

Unfortunately, yellow leaves are a generic symptom with a number of possible causes, including under or overwatering and improper light.

Make sure it is not off to the side of the window but close to a wall that would block most of the light it needs. Move it more in front of the window or out more from the wall, if necessary.

Allow the top half-inch of soil to dry before watering it carefully all around until some water trickles through.

Remove the yellow leaves so you can monitor its progress.

This plant is not technically a succulent but it wants to be treated like one. Let the soil dry an inch or so between good waterings. The top soil will look pretty dry by this time. To me your leaves look like overwatering, but as Will says yellow leaves come for several reasons.

Thank you!!