Dietes grandiflora is a rhizomatous perennial plant of the Iridaceae family, native to South Africa and known as the large wild iris, African iris or fairy iris.

Its long, stiff, fan-shaped, dark green, sword-shaped leaves can grow up to 1m long and 15-20mm wide. Large iris-like flowers are borne on erect, slender stalks about 1 m long. The individual flowers are white with yellow nectar ducts on the outer sepals and purple central segments, measuring about 10 cm across. They flower in succession over a very long period for much of the year. Individual flowers last no more than a few days, but the plant bears so many flowers at the peak that it is particularly striking when established, forming large clumps up to 150 cm wide. Dietes can be used as a tall ground cover when planted as a solitary border, as a single plant or in groups of 3 or 5.

It is an easy garden plant that will thrive in most conditions. Plants are both frost and drought tolerant and will grow in either sun or shade. However, for best results and the most flowers, plant Dietes grandiflora in full sun or light shade in a well-drained, well-composed soil and water well in summer.

Both the flower and foliage of Dietes bicolor are strikingly different, so it is nice to plant both for contrast.