Two types of plums are commonly grown: Japanese and European. The former are used only for fresh eating, whereas the latter can be used for fresh eating or, as is more common in Pennsylvania, for drying or processing.
Methley: An early ripening Japanese plum of good quality and appearance. It has round, sweet, very juicy purple fruit with a red blush. The flowers are partially self-fruitful, but the addition of Shiro or Ozark Premier will increase yields. It ripens around mid-July in southcentral Pennsylvania.
Shiro: A round, yellow Japanese plum with an occasional pink blush. Although they are clingstone, the fruits are very juicy. Harvest in southcentral Pennsylvania is around August 1.
Castleton: A dual-purpose prune/plum released by Cornell University. The fruit is blue, round, and similar in appearance to Stanley. Approximate ripening date is August 10 in southcentral Pennsylvania.
Ozark Premier: This Japanese type is a large, bright-red fruit with a tough skin. The flesh is yellow and juicy and of a fair quality. The flavor tends to be on the tart side. This is a clingstone fruit, but with a small seed. Harvest in southcentral Pennsylvania is around August 15. Will not pollinate Stanley or Bluefre.
BlueByrd: A European type plum developed at the USDA station in Kearneysville, West Virginia, and named for Senator Robert C. Byrd. The fruit is firm and sweet with a yellow flesh; it ripens around the middle of August.
Seneca: A second recent release from Cornell University. The fruit are large, reddish blue, and have excellent dessert quality. The fruit is reported to be resistant to cracking and to brown rot. Approximate ripening date is August 22 in southcentral Pennsylvania.
Stanley: A medium, dark-blue freestone that is oval in shape with a distinctive neck. The fruit is very well suited for processing and drying. The flesh is greenish yellow, juicy, and fine grained. Harvest is around the last week in August.
Long John: Developed at Cornell University, this European type produces large, long, teardrop-shaped fruit. The blue-colored fruit are freestone and ripen with Stanley.
Bluefre: A European type that produces large, blue, yellow-fleshed, freestone fruit. Fruit hangs well on the tree but produces many split pits. Harvest is approximately the first week in September.
A breeding program at Auburn University has developed a series of new plum varieties that have resistance to black knot, brown rot, and bacterial canker. These plums would be good candidates for homeowners that want to minimize their use of fungicides. Locating all of the varieties may be a little difficult. We currently do not have any experience with growing these varieties in Pennsylvania.
AU Amber: The fruit is medium sized with a purple skin and excellent flavor. Fruit is smaller than that of AU Rosa and AU Rubrum. Partially self-fruitful.
AU Rosa: The fruit has a bright-red skin with yellow flesh.
AU Rubrum: The fruit is large and firm with a maroon skin with red flesh. Reported to be self-fruitful.
AU Cherry: A small plum that has consistently
AU Roadside: Sometimes listed as "War Eagle!" in nursery catalogs. The red-skinned fruit and flesh is of high quality. Flowers are self-fruitful.