US Patent 7506473 Irrigation device

An irrigation device for delivering water to the roots of a plant include an elongated mass of capillary material bound together by an impermeable sheath with a pair of cone shaped ends. A sponge like filter covers an upper one of the cone shaped ends and a second porous filter covers the opposite end. A plurality of impermeable tapered rings are provided for blocking off one or more portions of the capillary material to prevent water from flowing through those portions.