A method of producing a virtually fireproof plywood from perennial grasses such as Arundo donax Ligneous, various bamboo strains, or a blend thereof, by first weaving the stalks of these plants into a mat and then layering these mats and binding each layer with any one of several commercial resins mixed with potash for the purpose of enhancing the board's fire retardant quality. The result is the formation of a finished product with structural board attributes and an exceptionally high flash point in relation to other manufactured board products made from forest materials.