Bulbous perennial of the Iridaceae family, 'Mammoth Yellow' is a horticultural cultivar belonging to the group of large spring crocuses with yellow flowers, related to Crocus flavus and its hybrids with other species with yellow tepals. Like all Dutch crocuses, these selections were developed and stabilized mainly in the Netherlands.
'Mammoth Yellow' is one of the most widespread and appreciated yellow cultivars of this group. Its flowers are a bright and pure golden yellow, particularly large for a spring crocus, with broad, well-fleshed, and rounded tepals that spread generously when open. The anthers are also yellow, giving the flower a uniformly golden tone, without color contrast but with great luminous intensity. The foliage features narrow, upright, dark green leaves, with the characteristic silver median line of the group.
In cultivation, flowering occurs in March-April, concurrent with other large Dutch crocuses, and the very name of the cultivar announces flowers of an extraordinary size for the genus.
It is cultivated in well-drained soil, in full sun, in rock gardens, borders, and lawns where it naturalizes easily. Its intense yellow, rare among large-flowered spring crocuses, makes it an essential element of early-season bulbous plantings.