2013 ASHS Annual Conference

The 113 named varieties of plums introduced by Luther Burbank (1849–1926) were by far the most numerous and arguably the most significant of his horticultural accomplishments. He began by importing 12 seedlings from Japan in 1885, including ‘Abundance’ and ‘Satsuma’ (Prunus salicina). The cultivars he released in the late 19^th and early 20^th century played a crucial role in developing commercial cultivation of Asian-type plums in California, the United States, and much of the world; they also served as founding clones for later breeders. His crowning achievement was ‘Santa Rosa’ (introduced 1906), which appears to have derived its reddish flesh from ‘Satsuma’; firmness and acidity from the apricot or Simon plum (P. simonii); and disease resistance and a rich wild aroma from a native American plum (P. americana). In 1961 ‘Santa Rosa’ accounted for 35% of the California plum harvest. Many of Burbank’s other cultivars of primarily P. salicina ancestry were extensively cultivated in California in the early and middle 1900s, including ‘Beauty’ (1911), ‘Burbank’ (1888), ‘Duarte’ (1900), ‘Eldorado’ (1904), ‘Formosa’ (1907), and ‘Wickson’ (1892). His most important introductions of European plum (P. domestica) were ‘Sugar’ prune (1899) and ‘Standard’ prune (1911). Burbank made use of at least 11 plum species, and including hybrids and selected seedlings of such native species as P. maritima (‘Improved Beach’, 1897; ‘Maritima’, 1899; ‘Peach’, 1901), P. subcordata (‘Nixie’, 1911), and P. munsoniana(‘Juicy’, 1893; ‘America’, 1898; ‘Victory’, 1911). Some of Burbank’s more obscure introductions never received general distribution and have disappeared; others such as ‘Santa Rosa’, ‘Shiro’ (1899), and ‘Elephant Heart’ (released posthumously in 1929) still are commonly cultivated today in home gardens and for sale at local markets. ‘Inca’ (1919), his best tasting plum, is much appreciated by fruit connoisseurs, although it has some obvious flaws for commercial use.