It takes on the shrubby form most often, with multiple leaders, but does grow as a small, single-stemmed tree in southern Alabama, Georgia, and Florida. Hi, Star: Yes, your American plum needs cross-pollination and in fact is an excellent cross-pollenizer itself. Abundant tiny white flowers open before the leaves emerge in spring. Flowers are white, 5-petaled, about 1 inch across, and borne singly or in clusters at the juncture of a stem and leaf. Prunus americana Marsh., American plum, is a deciduous large shrub or small tree with a broad crown, reaching heights up to 15 feet. About half of the varieties are self-fruitful and half are not. As well as being an excellent pollinator, the American plum is a beautiful landscaping tree with showy white flowers in spring and deep red fall foliage. The American Plum is a fast growing selection with many wildlife benefits. Plums appear in late summer. ... American - Self-fruitful Japanese - Three types of … Your Italian prune plum is probably self-pollinating (“probably,” because these days there are various hybrids out there with differing characteristics) but of course could still help the American… Wild plum, also called American plum is a small, fast-growing, short-lived, colony-forming native tree, commonly found along fencerows, open fields, and roadsides. American Plum (Prunus americana) is a small, deciduous, single trunk tree or multi-stemmed shrub which occurs in rocky or sandy soils in woodlands, pastures, abandoned farms, streams and hedgerows. Plum: A wide diversity occurs in the plums. An American wild plum tree doesn't exactly look like a tree, but it doesn't exactly look like a shrub, so I'm guessing that pruning has a great deal to do with your tree's appearance. A few European plum varieties such as Damson, Italian Prune, Valor, and Stanley are at least partially self-fertile but will generally yield better with cross-pollination. Plum trees (Prunus spp.) This plum will grow as a small tree or large shrub which will readily sucker from the ground up around the root zone. American plum (Prunus americana) is a deciduous fruit-bearing shrub to small tree (15 to 25 feet tall) that is winter hardy, has a broad crown and, most importantly, is thicket-forming. Japanese plum varieties need cross-pollination from another Japanese or Japanese-American hybrid variety. Fruits are red to yellow, almost globular edible plums about l inch in diameter. Pollination is the transfer of pollen from the male part (anther) of a flower to the female part (pistil) of the same or another flower of the same sort. Prunus americana, commonly called the American plum, wild plum, or Marshall's large yellow sweet plum, is a species of Prunus native to North America from Saskatchewan and Idaho south to New Mexico and east to Québec, Maine and Florida.. Prunus americana has often been planted outside its native range and sometimes escapes cultivation. As a tree, it typically grows to 15-25 feet tall with a broad, spreading crown. Although you can find plums that will grow in a variety of ranges, plums generally do well in zones 3-10. American Plum Prunus americana. As a shrub, it suckers freely and can form large colonies. Planting Plums Zones. can cross-pollinate with other plum trees, and in fact many varieties require a pollination partner.