Ontario plums belong to one of two types: Japanese and European. All are fine for eating but the European prune types are also well suited to cooking.
Both yellow and red are descended from Japanese plums; the blue plums and blue prunes are forms of European plums.
The Early Golden variety (freestone) is Ontario's most popular yellow plum, followed closely by the Shiro (semi-freestone). Both are round, firm-fleshed with yellow skin. They are generally on the market through July and August.
Major red varieties are Burbank, Ozark Premier and Vanier available in August and September, mainly at farmers' markets.
Popular eating plums are Bluefre, California Blue, Valor (medium to large size, blue skin, bright yellow flesh), Voyageur (smaller, yellow flesh, purple skin) Verity, Veeblue and Victory (dark purple skin, orange flesh). All are freestone but Valor, Veeblue and Voyager are semi-freestone. These plums are available until late October.
The two main prune types are Stanley and Italian.
One medium-size plum contains 36 calories and is a source of Vitamin C.
Wild plums native to North America were gathered and eaten by aboriginal peoples and European colonists alike.
European and Japanese plums, however, are more recent. The Japanese types were introduced to the New World only in the late 1800s, although both had been growing in their native areas for several thousand years.