Overwatering is a leading cause for succulent plant death. In warm, sunny areas, the plant can reach two feet in height. A south-facing or west facing window will likely require you to place your succulent at least a few feet from the window. However, String of Hearts can be kept directly in a north-facing, or east-facing, window. Lithops don’t need much fertilizer but you can still give them a bit every few weeks to help them grow strong and healthy. The aeoniums will go through the same dormancy behavior even if it's not in the summer months.