This is the most common myth associated with the hair care, and people often tend to believe this stuff. But, when you will think practically, then you will realize that this has nothing to do with the growth of your hair faster. The hair grows from your scalp and not from the end, and when you are trimming your hair, it is not making it grow faster rather you are making it short every time. The only true fact related with trimming your hair is that it helps you get rid of your split ends and make your locks look healthier.
For more info: side effects of applying vicks on hair