Abstract: Two designs for rooftop irrigation apparatus are provided. The apparatus employ sub-irrigation and wicking technology to nourish vegetation supported by the apparatus. The apparatus may be placed on outdoor surfaces such as roofs. The first apparatus comprises interlocking modules. The use of sub-irrigation technology enables the modules to sustain a wide variety of plant-life. In addition, the plants may be removed and replaced easily by other plants, including hydroponic plants and vegetables. The second apparatus is a tray that contains an array of wicked protrusions that may hold plant roots and nourish the plants through sub-irrigation. Both apparatus may utilize control systems to control the level of water underneath the vegetation. Excess water may be stored in an auxiliary tank for later use or discharged from the system to decrease apparatus load.