For the past three years, I've trimmed once per year, but when I finally trim, I need one baaaaaad, however, I use heat appliances. I used to trim once every three months and was cutting too much, so with my yearly trims, I'm retaining my length way better. In my opinion, unless a person is wearing there hair straight, there really isn't a need to trim very often. My ex boyfriend never trimmed his hair and his ends looked great, a few splits hear and there but nothing outrageous, and his hair got to the middle of his back...he kept is cornrowed.