In this video Urban Grower talks about grafting cannabis plants with Midnight Gardener at the Dampkring grow shop in Amsterdam.
Originally the guys at the Dampkring were experimenting to see if they could increase the yield of Cheese and Diesel by grafting cuttings from those plants onto the base of a Congo Haze plant that has a great root base that can transport lots of water and nutrients. The experiment found that the yield was not increased.
Though the yield of the Diesel or Cheese did not increase grafting cannabis plants has got benefits. The main benefit of grafting cannabis plants together would be the ability to save space in the grow room. A lot of people like to keep good genetics but this can take up a lot of space. Instead of having a mother plant for each strain you could have one mother plant with three, four five or even more strains grafted on which cuttings can then be taken from.