In agriculture, subirrigation is a method of irrigation used in commercial greenhouse operations. Water is delivered from below, absorbed upwards, and the excess collected for reuse. Subirrigation is usually used with potted plants .

Three basic types of subirrigation system are in general use: ebb-and-flow (bench-mounted enclosures holding pots are filled and then drained); trough (water is flowed through bench-mounted, slightly sloping enclosures containing pots); and flooded floor (special sloped concrete flooring is flooded and drained).

Subirrigation has been growing in popularity since the 1990s. Advantages are water and nutrient conservation, and labor-saving. The outfitting cost is relatively high. Potential problems, such as the possibility of increased presence of disease in recycle water, have only begun to be investigated.