I think this is the one plant that I hear the most questions about. I’m often reading that they are hard to keep alive and see tons of people saying they have killed theirs. If you know how to care for them, they are actually one of the easiest plants ever to own. Hopefully in this post I can clear up some of the confusion surrounding them and help yours to thrive!
Potting: I personally love terra-cotta pots for all of my cacti and succulents. String of Pearls is no different. They have fairly small root systems so you don’t need a large pot. Mine has been in a 6 inch terra-cotta for the last three years, to give you an idea. At the most I would go to an 8 inch pot and then be very careful with your watering. Also your pot must have drainage holes. As far as soil goes I’m a big fan of Black Gold Cactus Mix. But if you can’t find it where you are start with a high quality soil and add in a ton of pumice and some sand to make it well draining. String of Pearls really doesn’t like wet feet.
Light: String of Pearls is definitely one of the more greedy plants when it comes to lighting! It is going to be happiest directly in front of your brightest windows, they seriously need all the light. I have had great luck in my east and west windows. But mine lives in a window facing south. If you live in the Northern Hemisphere I would avoid placing them in your north windows, they won’t get enough light. Same goes for your south windows if you live in the Southern Hemisphere.
Thirsty pearls! 
Pearls that don’t need water!
Watering: Many people find pearls tricky when it comes to watering them. They are very easy to over water. If you got the soil composition right, have it a pot with drainage, and you have it in the right lighting, then watering is easy! Just wait for the pearls to show you that they are thirsty before watering them! Thirsty Pearls lose their vibrant color and get dull. They will also lose their round plump shape and get pointy and kind of pruny looking. Pearls that don’t need any water are plump and bright green. If you are unsure if you should water your pearls, wait a week or two then water. Unless you forget to water your Pearls for several months, you will not kill it from under-watering. However, over-watering is guaranteed to kill your Pearls.
Fertilizing: String of Pearls have low fertilizer needs. I may toss some Osmocote Plus on mine once a year if I remember. They are happy to have it, but they aren’t heavy feeders so it’s not critical for their growth.
Propagating and Pruning: Propagating Pearls couldn’t be easier! Just snip off some vines, pull off some pearls near where you cut and pot them up. Bury the vine where you removed the pearls then water. They will root in a few weeks and then you have a new String of Pearls plant! If your pearls are thin on top, just take a few vines and curl them around on the soil. Use pins to hold them down, the vines will root and start sending out new vines. Before you know it, your Pearls will be lush and full. Pruning SoP is easy, simply snip any vines that are too long. Then you can propagate those!
Toxicity: String of Pearls are toxic to people and pets. If ingested they can cause vomiting, diarrhea, and other gastric symptoms. They also can cause rashes if the sap gets on your skin.
Pests: SoP doesn’t seem to get many pests. But mealy bugs and scale are one to look out for.
Plant Brittanica 