an irrigation system ( for watering a substrate , comprising a pipe having a longitudinal dimension . a hermetically closeable inlet portions is connected to a water supply . a passageway extends generally throughout the longitudinal dimension and is in fluid communication with the inlet portion such that water can fill the passageway . openings are in fluid communication with the passageway such that water in the passageway can exit the pipe through the openings . the openings are distributed along the longitudinal dimension of the pipe , the pipe being adapted to be at least partially buried in the substrates with said longitudinal dimension being generally horizontal . porous members are secured to an outer periphery of the pipe so as to each cover one of the openings and so as to be in contact with the substrate such that water flows out of the passageway through the openings and the porous member and into the substrate as a result of a capillary action of the substrates .