I have grafted viridis to alba before but the plant died in a move , after the graft took I didn't really notice a reasonable increase in mass from the viridis , in fact, new growth from the alba would attempt to make new routes around the viridis. I think like most stocks the benefit to this is being able to plant it in a colder region or against a disease that attacks the roots, or for fun to practice grafting skills but I didn't really notice any much more growth improvements . And due to genetics I doubt that any increase in potency , except small in very small amount s would be noticed that couldn't be done with better soils and conditions . This is my thoughts on it , others may have had bigger plants survive and noticed completely different results , I find genetics to be the best choice for faster growth , p. Nexus, and for some reason a viridis cultivar I got from here s metabolism is faster than a lot of my viridis and sometimes on par with alba s I have .