(Prunus bessyi x P. ssp)

Background

Technically the term “cherry plum” is the common name for Prunus cerasifera of European origin, but the name is also used more regionally to describe crosses between cherries and plums. The term “cherry plum” as used in this website refers to cherry and plum hybrid crosses. Cherry plums, observed at Carandale, first became available in the late 1800s and early 1900s. Most of the original cherry plums were produced by crossing sand cherry (Prunus besseyi) with Japanese plum (Prunus salicina). Later cultivars were also produced from open pollinated cherry plums and by crossing cherry plums. Most have excellent quality for canning, jams, jellies, pies and juices, and some have dessert quality. Many are low-growing shrubs that produce heavily, making them well-suited for mechanical harvesting. Cherry plum requires cross-pollination. They grow best in sandy soils but most any soil will suffice as long as it is well drained. They do not tolerate waterlogged soils.

Observations at Carandale Farm

Two cultivars were established in the test plot in 2004, both purchased from St. Lawrence Nurseries.

Four ‘Compass’ trees were ordered as pollinizer plants. Two of them were mislabeled, and were actually American plums (P. americana), which are good pollinizers in their own right, but it did reduce pollinizer diversity. Pollinizer diversity is important because all Asian-American hybrid plums (and most other hybrid plums) require cross-pollination for fruit set. Every hybrid cross has a preferred pollinizer that is not always known or easily predictable. The integration of a diverse set of pollinizer species will assure that all cultivars will have adequate pollination. American plum, ‘Compass’ and ‘Toka’ were all included specifically as pollinizer cultivars. Fortunately, the two ‘Compass’ trees are located where they can provide good pollination coverage.

‘Compass’ is later blooming than most cultivars in need of cross-pollination. The photo shows the blossoms have not yet opened, while trees in the background are in full bloom. This mismatch in bloom time may reduce its effectiveness as a pollinizer for many cultivars. The other photo shows it as a very upright tree, atypical of most cherry plums that tend to be shrub-like. It has been observed to be unfruitful, and the few small cherry-like fruit it produces have a tart skin, limiting uses to jams and sauces. Fruit typically ripens mid-August.

Four ‘Sapalta’ trees were ordered and planted as part of the replicated trial, not as a pollinizer species (though they may also be good pollinizers for other hybrid cultivars). The trees transplanted well and adapted to the site. All four remain healthy and productive. As the photos show, they are more typical based on the general introductory description of cherry-plum. ‘Sapalta’ has some impressive qualities:

• The shrub-like trees could be managed for mechanical harvesting.
• They are the second plum to ripen. (‘Black Ice’ being the first)
• There is minimal loss from insects and disease, but it does seem to have an above-average fruit splitting response to excessive rainfall just prior to harvest.
• It fruits heavily and consistently. (see photo)
• The fruit is dark purple on the outside with nearly black flesh, possibly indicating a high anthocyanin content (Marini, 2009).
• The skin is tart with a hint of tannin, making the fruit less desirable for fresh consumption, but a good choice for processing. The dark purple fruit make an attractive and rich-looking finished product that is probably nutritionally rich as well because its intense pigmentation indicates a high anthocyanin content.
• The fruit is nearly freestone, making it easy to pit and process.
• As an added bonus, ‘Sapalta’ puts on a spectacular fall display with its red foliage. (see photo)

References

University of Saskatchewan College of Agriculture and Bioresources, click on Cherry Plum
Marini, RP. “Growing Cherries in Virginia.” Virginia Cooperative Extension, 2009, Pub 422-018.

This article was posted in Prunus.