A plant growing method, including the steps of: planting the plant (16) in a first compartment (70) of a planter (10)； allowing roots (18) of the plant (16) to grow from the first compartment (70) into a second compartment (72A) of the of planter (10), while the first (70) and second (72A) compartments are not partitioned； cutting horizontally the grown roots (18) by partitioning (22) the first compartment (70) from the second compartment (72A) by a saw (52), disposed at the bottom of a vertical partition (20A)； and removing the cut roots (18) from the second compartment (72A), thereby allowing the cut roots (18) to further grow from the first compartment (70) into the second compartment (72A).
