The present invention relates to a portable modular drainage system that is attached to a series of cylindrical planting containers. The system comprises a plurality of peaked modules with opposing, convergent curved side walls designed to conform to the curve of a planting container. Between each side wall is a notch which accepts one or more containers and firmly connects the module to the containers. The modules are preferably designed in four distinct shapes, one with quadrature symmetry for connecting four containers at once, one smaller triangular unit which connects three staggered containers, one three-legged unit that connects two containers which are positioned at an edge of a plant farm, and one edge unit designed to connect three staggered containers at the end of three rows. When these modules are appropriately connected to the containers, they effectively drain the water that would otherwise have fallen between the pots directly into the pots. Not only does this system save up to 20% of water that would otherwise be lost between containers but it also prevents unwanted weed and grass growth between the containers by depriving it of water, and helps to prevent the containers from being blown over.