A method of inoculating a tree with an ectomycorrhizal fungus is disclosed. The method comprises contacting at least one non-terrestrial adventitious root of the tree with the ectomycorrhizal fungus under conditions suitable for inoculation of the at least one non-terrestrial adventitious root by the ectomycorrhizal fungus. Methods of cultivating the ectomycorrhizal fungus are also disclosed as well as systems and devices for same.