I rarely fertilize as well. All of my plants are grown indoors. I have a liquid fertilizer for succulents that gets heavily diluted in water, and if I do fertilize, I just give it to them when they start actively growing in spring, and that's really it. The bottle recommends every few weeks, but I just do once in spring for a little boost. Unless the plants are being repotted with fresh soil, then I don't bother.