Wrong. A haircut has no effect on the rate of hair growth. Trim it or not, hair grows at the rate of one inch per month. Hair growth will not be affected by trimming the hair end. The only proven factors that affect rate of hair growth are genetics, hormones, and diet. However, chopping of the split ends may promote better hair growth. As the presence of split ends impede healthy hair growth. Avoid split ends by preventing over-styling in the first place is more effective for healthy hair growth!