When Are Japanese Plums Ready to Harvest?

Fruiting Season

• Plums beginning appearing on Japanese plum trees shortly after the flowers begin to fade and production decreases. The actual time frame for plums beginning to sprout depends greatly on the type of Japanese plum and the location. For example, Autumn Rosa plums mature around Labor Day in California, while those from a Shiro tree mature much earlier, usually around Independence Day.

Geographical Considerations

• The timing of harvest for Japanese plums is affected by the location's elevation and latitude coordinates. For example, fruit maturation occurs earlier in the southern U.S. than in the northern and central areas of the country. Areas that contain mountains and slopes experience a later maturation than low valley areas. The Nubiana variety, a mid-season Japanese plum, matures in early August when planted in the Sacramento valley, but not until late August or early September in the more central or eastern areas.

Harvesting by Appearance

• The best way to tell if your Japanese plums are ready for harvest is by the skin color and firmness of the fruit. When plums are mature they turn an amber color from their original green-yellow color. They also reach 25 to 35 percent solid and have 1 to 2 pound firmness. Test for firmness by pressing gently into the plum, and if it's beginning to get soft then it's ready to eat.

Harvesting

• When harvesting Japanese plums that will be eaten, you need to hand pick them from the trees. This will keep them from becoming bruised or otherwise damaged. Plum trees need to be picked at least two to four times over a seven-to-10 day span for optimum freshness. When harvesting plums for drying or canning, the shake-and-catch method can be used. Once harvested, plums are best kept at 31 to 32 degrees Fahrenheit for two to four weeks.