The length of time it takes to grow Cannabis is highly dependent on a myriad of factors. For this reason, plants could take anywhere between 9 weeks and 7 months. The average growth period, however, for many of the Cannabis plants is 4 months. Listed below are some of the factors that heavily influence the amount of time taken prior to the harvesting of the plant: The strain of the plant There are numerous Cannabis strains that farmers could choose from, and each of these strains has their ...