Molasses is typically used in the final 3-4 weeks of flowering. It is an easy way to boost sugar content in the buds and, when used properly, will result in tastier, sweeter buds as well as increased essential oil production. If you don't want to use molasses or are unable to find the right kind (blackstrap is best), you can buy sweet solutions made especially for gardening applications. I use "Sugar Daddy" made by Technaflora Plant Products because, in addition to the sweet stuff, it supplies essential amino acids.