Description Shiro is a classic yellow Japanese plum valued for sweet, mild flavor and very heavy production. It is best enjoyed fresh, and because it sets so heavily, thinning is essential for achieving larger, higher-quality fruit. Introduced in 1899 to the US, Shiro became popular for its reliable cropping and approachable eating quality. The fruit ripens to a translucent golden yellow with tender flesh that is juicy and pleasant rather than sharp. Left unthinned, Shiro produces an abundance of smaller plums. With proper thinning, however, the fruit size increases dramatically, turning a heavy set into fewer but genuinely impressive yellow plums. This responsiveness to thinning is one of Shiro’s defining traits and the key to getting the best results. Overview Japanese plum with yellow skin and yellow flesh Sweet, mild flavor suited to fresh eating Extremely heavy producer Fruit size improves significantly with thinning Partially self-fertile; benefits from a pollination partner Growing Details Latin Name: Prunus salicina ’Shiro’Site and Soil: 1/2 day to full day of sun; well-drained soilChill Requirement: Approx. 450–500 hoursHardiness: USDA Zone 5–9Rootstock: Marianna 2624Bearing Age: 1–3 yearsSize at Maturity: Typically maintained at 10–14 ft tall and wide with pruningFlowering Time: Early flowering (within plum / pluot types)Ripening Time: Early to midseason (within Japanese plums); timing varies by regionPollination: Partially self-fertile; plant a compatible Japanese plum within 20–30 feet for best yieldsPests & Diseases: Standard plum considerations; good airflow is beneficialYield: Very heavy without thinning Additional Notes Grower’s Insight: Shiro’s quality is unlocked through thinning. Reducing the crop early transforms fruit size and finish. Regional Insight: In cool or wet spring climates, early flowering means pollinator activity can be limited—support early-season pollinators and avoid spraying during bloom. Best eaten fresh; fruit softens quickly once ripe. Explore more plums in our collection: Plum Trees
