Some type of begonia? Photos? Was is with other shade plants or with the sunny hanging baskets?

These can be a bit tricky but they're tougher than they look. Sounds like yours has a rootball which is thirsty, but can't take up they water from a hardened off rootball. So, you can soak it in an inch or 2 of water, or take it out of pot first, rough up bottom roots & soak for a while. OR, poke some holes in the top of the mix & water directly into them. In several months you might remove the mix from the roots completely & refresh w/ new mix. A few yellowing leaves can be removed, no problem. Also, I'd remove that mossy stuff, doesn't help the plant & just gives insects a potential home. One of mine, showing some of its tubers. I usually cut these back every year or 2 & restart them. They sometimes look scrappy, & can benefit from restarting. One can take stem or tip cuttings & root them in water, too.

Hey everyone, is my string of hearts too dry? Does it need more soil added to the top? The new baby leaves and oldest leaves turn yellow and wilt off. Any advice?

Since these types of plants are often propagated with multiple cuttings, it's possible that one strand just was never seated well in the soil or never fully developed good roots. So it never got enough water and the roots on that strand dried up. If the rest of the plant is healthy, I wouldn't worry too much about it. You can inspect the other strands at the base of the soil. Also, you may still be able to root that piece that came out. Remove the lower set of leaves and stick the strand in a small glass of water or dampened perlite. They develop roots fairly easily. If the leaves on it are still strong, you could propagate using the "butterfly method". This is what I did with the strands someone gave me recently. You can google it up. But basically, you cut the strand in pieces between each set of two leaves. Then lay them on top of some dampened soil or perlite and sort of push them down a bit to make contact. Wait. They will eventually start to grow. This was started about two months ago from a single strand that I cut up like that.