Vertro HM is a mixture of 75%, by volume, of our high quality Vertro Biochar with 25%, by volume, of Mt. Holyoke volcanic,  paramagnetic,  basalt flour  mined from the Mt. Holyoke range in  Western Massachusetts.   We add dry spore  endo  mycorrhizal  fungi to this  mixture to  promote  healthy  microbial activity  in the root zone.  The dry spores are completely stable until they are activated by enzymes produced by the roots of the plant. This mixture provides  all  the benefits of  high quality biochar as  well as  important  minerals and fungi to establish a healthy web  of soil  biological  life to replenish depleted soils and maximize  nutrient density of crops.  It is ready to use according to package instructions. Available in 40 cup and 15 cup bags.