Centuries of cultivation and selection have given us a wide variety of plum fruits, both large and small. Different plum tree varieties have different pollination requirements; the fruits have a wide range of textures and uses in your kitchen including fresh eating, jam making, drying, baking, sauces, salsas, chutneys, vinegars, and making alcoholic beverages. Below is a brief list of the different types of plums trees you can plant and cultivate in your own orchard.
So exactly what is a European plum? What does it look like and how does it taste? European plum trees produce plums with skins in a wide variety of colors – generally purple or yellow, although popular ‘Green Gage’ and Persian plums are often green. Many European plums are freestone and less juicy than Asian plums and are often canned, dried, or made into jams or chutneys. European plum flavor varies from intensely sweet to complex and floral, with different kinds of plums developed for different uses.
The main characteristic of the Damson is its distinctive intense flavor. Unlike many other European plums, Damson plums are both very high in sugar AND astringent compounds that give Damson its unique and complex flavor. Despite being clingstone, Damson plums are almost exclusively cultivated to create the most rich and wonderful plum jams. The trees are very reliable producers of heavy loads of fruit.
Prune plums are characterized by their high sugar content and low moisture content, creating a fruit that dries quickly and stores for long periods without refrigeration. Different kinds of prune plums originate from various parts of China, the Middle East, and Europe, with French and Italian prunes being the most commonly known.
Mirabelle plums are a special kind of European plum that is both smaller and more intensely flavored than many classic culinary plums. Despite being smaller than most plums, Mirabelle plums are exceptionally easy to pit and process, with an incredible floral flavor that has caused them to be one of the most sought-after fruits grown in France.
So exactly what is an Asian plum? What does it look like and how does it taste? Generally Asian plum trees produce plums with thin, tart skins in a variety of colors and shapes. Usually red, purple, or yellow and round or oblong, Asian plums are much juicier than many European plums. These qualities make Asian plums very popular for fresh eating and making salsas, vinegar, sauces and wine, but not as useful for standard cooking applications.
In recent years plum hybrids have become extremely popular for their intense and unique sweet flavors and novel skin colorations. Plum hybrids include pluots, pluerries, plumcots, apriums, and nectaplums. Complex crosses have some specific pollination and growing requirements, but they are definitely worth the extra time and effort to grow. They are reliably pollinated by Asian plums that produce a lot of pollen, like Shiro, Toka, Beauty, and Santa Rosa.
Size in both European and Asian plum trees is dictated by the rootstock they are grafted onto. We generally use two rootstocks, Marianna 2624 and St. Julian A. Both will produce a semi-dwarf sized tree between 10'- 15' feet tall, with some minor differences.
Marianna 2646 produces a larger semi-dwarf tree (80% of vigor) that can be easily maintained from 12 to 17 feet tall at maturity through regular pruning. This rootstock tolerates wet soils and has good disease resistance; it's moderately resistant to phytophthora, crown rot, root rot, and oak root fungus, as well as root-knot nematode resistant. Marianna 2624 can sucker in adverse conditions. Hardy to USDA zone 4-10.
St. Julian A
St. Julian A produces a mid-sized semi-dwarf tree (75% of vigor) that can be easily maintained from 10 to 15 feet tall at maturity through regular pruning. This rootstock tolerates a variety of soil conditions including wet and heavy clay. St. Julian A is particularly good for colder environments with fluctuating early spring temperatures. Hardy to USDA zone 3-9.
Plum pollination is achieved primarily through pollinating insects. Self-fertile plum varieties provide self-compatible pollen to produce fruit and will openly pollenate other plum trees flowering at the same time, including those of the same variety. Plums varieties that are not self-fertile will require another variety of plum flowering at the same time to cross-pollinate. Below is a handy reference for plum pollination.
In general plums are considered a summertime fruit, ripening anywhere from 140-170 days from the end of the bloom period. Asian plums usually ripen earliest in the season, followed by complex cross varieties, and then European plums - some of which will continue ripening into the beginning of fall.