Cultivar 160: Oka

Oka is a cherry-plum in the Hansen group, a sand cherry and plum hybrid developed from Champa. It is generally described as having Prunus besseyi x Japanese plum background.[S1] [S6] [S22] Later references narrow this to a seedling of Champa, probably a P. besseyi x P. salicina hybrid, while the prairie index lists it as P. besseyi 'Champa' x unknown.[S4] [S5] [S7] It was introduced through the South Dakota Agricultural Experiment Station, and sources tie it to 1924.[S5] [S8]

Hansen named Oka among the hybrid fruits he originated and introduced from his sand cherry breeding work.[S6] In South Dakota literature, it appears with Sapa and Opata as one of the most widely grown cherry-plums and as one of the dwarf so called tree fruits valued for bearing very quickly after transplanting.[S1] [S2] Recommendation tables place it among Hansen cherry-plums suitable for all South Dakota fruit zones, showing how broadly it was regarded across the state.[S2]

Prairie descriptions present Oka as a medium to fairly small fruit, about 1 inch or roughly 2.5 to 3.0 cm, roundish, with purplish red skin and very dark purplish red flesh.[S5] [S8] The skin is described as thick and tough. The flesh is firm, juicy, sweet, and pleasant, with good overall quality.[S8] One table lists it for fresh use, while South Dakota processing notes say Oka was especially valued for preserves because of its rich red color and the high quality of the finished product.[S5] [S1]

Sources place its season from mid August into early September.[S8] Prairie notes add that the fruit can remain edible on the bush for about three weeks after ripening.[S8] South Dakota guidance also notes that fruit not handled at once could be quick frozen and later used without losing excellent flavor.[S1]

The plant is usually described as bush like rather than tree like. General Hansen cherry-plum guidance says these hybrids grow rapidly, are best kept in bush form, and bear best on young wood. Pruning is aimed at renewing shoots rather than forcing a single trunk.[S1] Oka itself is described as a small upright bush with fine branches, and it was noted as productive at Rosthern.[S8] South Dakota extension material also grouped Oka with the early bearing cherry-plums that could fruit the year after transplanting.[S2]

Its hardiness is shown more by geography and recommendation history than by explicit zone numbers. Oka was recommended for all South Dakota zones, listed by South Dakota nurseries, and recorded as productive at Rosthern, Saskatchewan. Together these place it firmly in northern prairie fruit culture.[S2] [S3] [S8] The evidence supports it as a hardy prairie cherry-plum, though the packet does not give a direct USDA zone statement.[S2] [S8]

Oka also matters as part of the larger prairie breeding story around Champa, Sapa, and Opata. It belongs to the early wave of sand cherry x plum hybrids that helped define hardy plum breeding on the northern plains.[S1] [S6] Later prairie breeding records show Oka appearing in related breeding clusters and comparison tables, which suggests it remained useful not just as a fruiting cultivar but also as breeding material within that hardy Prunus lineage.[S5]

Summary source basis

• S1: New Hardy Fruits for the Northwest
• S2: South Dakota Fruit Garden
• S3: Nursery Plants Available from South Dakota Nurseries
• S4: 9c684c14 7509 4b78 a803 0bf01a64aa28
• S5: An index of fruit cultivars tested or developed on the Canadian prairies.
• S6: Northern Plant Novelties for 1944
• S7: Plant Introductions
• S8: TreeFruitsGrownInPrairieOrchards WRLeslie 1946 HQ

This summary currently draws chiefly from TreeFruitsGrownInPrairieOrchards WRLeslie 1946 HQ, with 7 additional supporting sources linked below.

Featured source descriptions

“'Oka' 7”
— ^[6]

“Usually comes into bearing the year after transplanting, practically as early as berries.”
— ^[5]

“Used as an example supporting inclusion of tree fruits even where quick returns are desired.”
— ^[5]

“One of the most widely grown cherry-plum hybrids.”
— ^[4]

Direct parent cultivars

• No direct linked parent cultivars promoted yet.

Parentage claim text

• Listed as P. besseyi 'Champa' x unknown.

Derived or downstream cultivar links

• No derived or downstream lineage links yet.

Source-story quotations

• Oka 16 F Early Medium Sand cherry hybridPollination Studies with Stone Fruits, p7
• Oka 16 F Early Medium Sand cherry hybridPollination Studies with Stone Fruits, p7
• Oka 16 F Early Medium Sand cherry hybridPollination Studies with Stone Fruits, p7
• HANSEN PLUMS FOR ALL ZONES | Cherry-Plums | other | OkaSouth Dakota Fruit Garden (visual sample pages 9-11), p1

Taxonomy context: No family-tree context surfaced yet.

Related cultivars mentioned in source context