Plant in sun or light shade. Although a wetland plant, yellow flag iris is surprisingly tolerant of drier conditions and can get by on only occasional irrigation but is happiest growing in shallow water. It is quite hardy and useful in USDA Zones 5a and above but it spreads vegetatively by rhizomes and by also by seed that spreads by floating on water and is reported as an invasive plant in Oregon and many eastern states in the US as we as in South Africa.

Iris pseudacorus is native to wet sites throughout Europe south into North Africa and east through Asia Minor. The genus Iris gets its name from the Greek goddess Iris, who was goddess of the rainbow. In Greek mythology, Hera, who was Queen of Olympia, was impressed by Iris' purity and honored her with a flower that bloomed with all the colors in her robe. The specific epithet means "false acorus" in reference to this plant's leaves similarity to those of the Sweet Flag, Acorus calamus (sweet flag) since they are both sword-shaped and have a prominently veined mid-rib.

We grew this plant when we were growing many other aquatic plants from 1994 until 2010 as part of our Aquatic Plants Program and we still have plants of this species and a dwarf cultivar in our ponds. 

The information about Iris pseudacorus displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant.