You asked a good question about our products and the lovely Goldcrest cypress. Yes, the numbers after different Hormex products refer in a shorthand sort of way to the strength of the product. This range of IBA concentrations really sets Hormex apart and makes your job as a propagator more successful. The numbers range from Hormex #1 to the most concentrated, #45, indicating their relative strengths. #45 is reserved for plants such as Juniperus sabrina ‘Tamariscifolia’, aka Tam or Tamarix juniper, that are notoriously reluctant to root. In the case of Goldcrest, a cultivar of the famed Monterrey cypress, I suggest Hormex #3 to start. But since I have not rooted this one myself, I reserve the right to also suggest #8 if #3 does not yield healthy clones.