A method for cultivating plant products without soil, comprising the following steps: a) providing at least one cultivation shelf, which comprises one supporting frame and a plurality of seeding and growth bars made of polymer material, which are easily removably coupled with said supporting frame and are arranged substantially coplanar to each other in parallel positions, side by side, said seeding and growth bars are rods, the seeding and growth bars extend straight along respective longitudinal axes, and are provided with seats which are adapted to house seeds and/or pills containing said seeds, said seats are made by concave recesses having on the corresponding bottom walls respective through openings structured for being traversed by, and remaining in direct contact with, the roots of the plant products during growth thereof, said seats are arranged longitudinally one after another along said respective seeding and growth bars spaced apart from one another and internally without any layers or substrates for the support or gripping of said roots of said plant products, b) selectively placing said seeds and/or said pills containing seeds into the respective seats so that the seed and/or pill rests directly on, and is in contact with, the inner surface of the seat thereof without any interposition of support layers or substrates between said seed and/or pill and said through opening of said seat; c) supplying fertilizer-based substances to the seeds and/or said pills contained in said seats of said seeding and growth bars. a) providing at least one cultivation shelf, which comprises one supporting frame and a plurality of seeding and growth bars made of polymer material, which are easily removably coupled with said supporting frame and are arranged substantially coplanar to each other in parallel positions, side by side, said seeding and growth bars are rods, the seeding and growth bars extend straight along respective longitudinal axes, and are provided with seats which are adapted to house seeds and/or pills containing said seeds, said seats are made by concave recesses having on the corresponding bottom walls respective through openings structured for being traversed by, and remaining in direct contact with, the roots of the plant products during growth thereof, said seats are arranged longitudinally one after another along said respective seeding and growth bars spaced apart from one another and internally without any layers or substrates for the support or gripping of said roots of said plant products, the seeding and growth bars extend straight along respective longitudinal axes, and are provided with seats which are adapted to house seeds and/or pills containing said seeds, said seats are made by concave recesses having on the corresponding bottom walls respective through openings structured for being traversed by, and remaining in direct contact with, the roots of the plant products during growth thereof, said seats are arranged longitudinally one after another along said respective seeding and growth bars spaced apart from one another and internally without any layers or substrates for the support or gripping of said roots of said plant products, b) selectively placing said seeds and/or said pills containing seeds into the respective seats so that the seed and/or pill rests directly on, and is in contact with, the inner surface of the seat thereof without any interposition of support layers or substrates between said seed and/or pill and said through opening of said seat; c) supplying fertilizer-based substances to the seeds and/or said pills contained in said seats of said seeding and growth bars.