Another great option is a natural fertilizer with an equal mix of NPK (5-10-5). It's a wonderful choice!
Crassula tetragona dropping leaves
You might be watering it a little too much during the dry season. I've found that once every two weeks is plenty, and then once a year, you can give it a little boost with slow-release fertilizer Osmocote (14-14-14). That should help it stay happy!