Much of the reading I'm doing seems to suggest that fertilizer is a must or at least strongly encouraged. But I'm having trouble finding much good info about pets, safety and pet-safe fertilizers. Are there alternatives to fertilizer, like realllly good mulch or packaged compost or something, that could keep vegetables fed and happy? Or any fertilizer options that pose zero risk to pets? I am in an apartment, so there's kinda no separation between plant area and pet area.