Plums are a globally significant stone fruit, and the United States is a major contributor to worldwide production. These fruits, a member of the Prunus genus, are cultivated across the country, though not uniformly. The success of plum growing depends entirely on matching the specific needs of different plum types with regional climates. The domestic market benefits from a wide range of plums, from those consumed fresh to those processed into dried products.
The Dominant Growing Region: California’s Role
California is the primary source for commercial plum production in the United States, accounting for over 90% of all fresh plums grown domestically. This dominance is tied to the unique Mediterranean climate found in the state’s interior.
The Central Valley, particularly Tulare and Fresno counties, serves as the hub for production. Plum trees flourish here due to mild, wet winters that satisfy chilling hours and subsequent hot, dry summers that allow the fruit to ripen fully and develop high sugar content. Furthermore, low humidity during the summer minimizes the risk of fungal diseases that can plague stone fruit in wetter climates.
The majority of fresh market plums grown in California are Japanese types, which have a lower winter chilling requirement than European counterparts. This allows for successful, high-volume commercial cultivation across the irrigated lands of the San Joaquin Valley, supporting a long harvest season from late spring into early autumn.
Secondary Production States and Regional Diversity
While California dominates the fresh market, other states contribute significantly to the overall plum and prune supply, especially for processed products. The Pacific Northwest, encompassing Washington and Oregon, is important for growing European-type plums destined for drying or canning. These cooler regions are better suited for varieties that thrive in temperate conditions.
Idaho and Michigan focus on varieties that exhibit greater cold hardiness. The growing season in these northern states is shorter, and the harvest typically begins later in the summer, around mid-August. Production often involves European plums, which are traditionally used for making prunes due to their high sugar content.
Cooler climates support the cultivation of specific European cultivars that are excellent for processing, offering a distinct market segment from fresh Japanese plums. This regional diversity ensures a steady supply of plums and prunes with varying characteristics throughout the year.
Major Plum Varieties Cultivated in the US
Commercial plum cultivation primarily revolves around two major species: the Japanese plum (Prunus salicina) and the European plum (Prunus domestica). Japanese plums are generally rounder, larger, and have a juicier, softer texture, making them the preferred choice for the fresh market. They are available in a wide array of colors, including red, black, and yellow-skinned varieties.
European plums are typically oval-shaped and have a firmer flesh and higher sugar content. This composition makes them ideal for drying, though a small percentage is also sold fresh. The European varieties are often self-pollinating and are known for their dark purple or blue skin.