Plant irrigation apparatus is provided with a reservoir. Water is placed inside the reservoir filling a portion of its volume. A pressurized gas is also introduced into the reservoir. The water is forced by the gas pressure out of the reservoir through at least one outlet conduit communicating with the water in the reservoir. Water leaves the outlet conduits through at least one discharge outlet. The apparatus can include structure for hanging the apparatus from a plant grow pot. Gas pressurization apparatus is utilized to provide a substantially constant supply of pressurized gas in the reservoir.