Overview
In the United States, nearly all of the commercially grown plums are hybrids of the Japanese plum introduced by Berkley nurseryman John Kelsey in the 1870s and subsequently hybridized by Luther Burbank in the late 1800s (California Tree Fruit Agreement). Today, California is the dominant producer of plums due to its mild winters, minimal rainfall during the growing season and low humidity, which is ideal for the Japanese varieties. California fresh plum harvest lasts from mid May through early October because of the many varieties. Plums are graded on maturity and sized based on the number of plums per standard 28-pound volume-fill box (California Tree Fruit Agreement).
California is the dominant producer of plums, accounting for over 96 percent of the 122,000 acres dedicated to both fresh plum and prune (dried plum) production in the United States in 2004. Fresh-market plum production accounts for roughly one-third of the total plum-bearing acreage (NASS). February 2006 . . . Plums