I know others that have planted Kalanchoe Delagoensis 'Chandelier Plant' in the same pot as other succulent plants with no problem. If your String of Pearls have been in a potting mix for more than a year, the nutrients may have leaked from the lack of watering. I, for one, have been guilty of neglecting this important plant and not paying enough attention to my String of Pearls. Sunburn or sun injury is the most common reason Strings of Bananas turn to brown.