High-value medicinal uses of non-psychoactive non-tetrahydrocannabinol (THC) hemp extracts like cannabidiol (CBD) are expanding to help reduce pain, severity of epileptic seizures and anxiety. This has stimulated the expansion of large indoor Cannabis grow operations in several markets. One key problem facing indoor cannabis producers is finding solutions to increase yield without significantly increasing operating costs. The purpose of this work was to evaluate how inoculation with a new sustainable microbial biostimulant, Mammoth P, developed at Colorado State University, affects plant growth rates and characteristics in Cannabis sativa. Treatment with Mammoth P led to significant increases in bud yields in Cannabis sativa by 16.5%. This increase in yield was accompanied by increases in plant height, and basal stem area. Increasing yield using this sustainable technology will help offset these capital expenses, reducing risk and likely increasing net income for indoor propagation facilities in this newly emerging market.