What is the typical growth duration of a marijuana plant? The growth cycle of cannabis plants can take anywhere from 10 to 32 weeks, from seed to harvesting its buds. The duration of the growth cycle can be shortened if starting with clones or autoflower seeds. The large discrepancy in growth cycle can be attributed to the vegetative stage and the location of growth, with indoor growers having more control over variables such as light and temperature, while outdoor growers have less control. #th