Dolgo

A Siberian crab brought from Russia to South Dakota in 1897 and introduced in 1917 for its ruby-red jelly

History

Dolgo is a crab apple that the horticulturist N. E. Hansen brought to South Dakota from Russia in 1897; his station at Brookings, the South Dakota Agricultural Experiment Station, introduced it in 1917 as “a new red-jellied Siberian crab”^1,2. The station listed it among its seedlings of the Siberian crab apple, Malus baccata¹. A bulletin of 1958 records that the seed which gave Dolgo and its near twin, Alexis, was collected in 1897 near St Petersburg (the bulletin’s Leningrad)^2,1; Hansen himself wrote in 1929 that Dolgo was a direct importation from Russia whose pedigree was not known³. The Secrest Arboretum of the Ohio State University derives the name from the Russian долго, which it translates as “long”, for the shape of the fruit, or “a long while”⁴.

Visitors to the station’s exhibits at the South Dakota State Fair, Hansen wrote, often asked about its “remarkably long conical, intensely bright red crabs”¹. In 1924, in answer to repeated requests, the station sent out seedlings of Dolgo and other named Siberian crabs¹. By 1958 more commercial nurseries listed Dolgo than Alexis, from which it is almost impossible to tell apart².

The fruit

The fruit is long and conical, about 2.5 to 3 cm across, and brilliant red all over^1,2. Hansen found it “full of juice”¹. At Brookings it ripened in September and dropped freely².

Growing

Hansen described a vigorous, productive tree, early and heavy in bearing and “thus far free from blight”, and young trees with wide forks and strong limbs unlikely to split¹. In the station’s collection in the 1950s it was among the hardiest plants; it began to bear very young, its alternate bearing was very noticeable, and it showed “remarkable resistance to blight and scab”². It has also been rated “Superior” for resistance to scab in evaluations by the International Ornamental Crabapple Society, with fewer than 5 per cent of leaves affected⁴. Dolgo is diploid⁵.

Uses

Hansen introduced Dolgo as a jelly crab, writing that the fruit “jells easily” into “a rich, ruby-red jelly”¹, and the 1958 bulletin counts it among the best crabs for jelly making². It is also an ornamental, with white flowers and, in late summer and autumn, a tree laden with red fruit^2,4. Its seedlings make good rootstocks, though their wood is so hard that grafting is difficult²; the Secrest Arboretum also values it as a rootstock and recommends the fruit for cider and apple butter⁴.

Where the sources disagree

How it came to South Dakota. Hansen wrote that it was brought over from Russia in 1897 and was a direct importation^1,3; the 1958 bulletin says it grew from seed collected near Leningrad that year²; the Secrest Arboretum, from seed gathered at the Imperial Botanical Gardens in St Petersburg⁴.
Its species. The South Dakota station counted it a Siberian crab, Malus baccata^1,2. In 1929 Hansen discussed it among crosses of the Siberian crab with the orchard apple and called its pedigree unknown³. The Secrest Arboretum calls it a seedling of Malus × robusta, a hybrid of the Siberian crab and the plumleaf crab, Malus prunifolia⁴.
Size and season. The 1958 bulletin’s text gives the fruit as about 2.5 cm (1 inch) across and ripe in early September; its table, about 3 cm (1¼ inches) and mature on 15 September².

Where Dolgo came from.

Sources

Plant Introductions (1895–1927), Bulletin 224, pp. 6, 7 and 11: Dolgo Crabapple, N. E. Hansen, Agricultural Experiment Station, South Dakota State College, Brookings; Open PRAIRIE, South Dakota State University, 1927-05. Supports: Dolgo "Introduced 1917" as "A new red-jellied Siberian crab"; the "remarkably long conical, intensely bright red crabs" asked about at the department's exhibits at the South Dakota State Fair; "one brought over from Russia in 1897"; a vigorous, productive tree "thus far free from blight"; fruit "full of juice" that "jells easily" into "a rich, ruby-red jelly"; nursery trees with wide-spreading forks and strongly shouldered limbs, unlikely to split; winning favour for its freedom from blight and its early and heavy bearing (p. 11); listed among the station's "Siberian Crab seedlings" with Alexis, Amur, Ivan, Beauty and Nocalyx (p. 7); seedlings of Dolgo and other named Siberian crabs distributed on repeated request in 1924 (p. 6); N. E. Hansen, horticulturist, and the department's work at Brookings; Alexis from seed from the Imperial Botanic Gardens at "St. Petersburg, now Leningrad".
Preliminary Evaluation and Description of Domestic and Introduced Fruit Plants, Bulletin 471, pp. 10–11, 13 and 16–17: Alexis and Dolgo, S. A. McCrory, Agricultural Experiment Station, South Dakota State College, Brookings (North Central Regional Publication 90); Open PRAIRIE, South Dakota State University, 1958-06. Supports: "Dolgo-M. baccata", from the same source as Alexis and introduced in 1917; the lot of seed that "produced Alexis and Dolgo" collected near Leningrad, Russia, in 1897 by N. E. Hansen (p. 13); one of the most winter-hardy plants in the collection; fruit long conic, "about 1 inch in diameter", skin brilliant red, the fruit-laden tree attractive in the fall; one of the best crabs for jelly making; ripening in early September and dropping freely; alternate bearing "very noticeable"; bearing at a very young age; "remarkable resistance to blight and scab"; almost impossible to tell from Alexis, though listed by more commercial nurseries; strong, well-spaced scaffold branches and a very vigorous tree; "Seedlings make good root stocks, but the wood is very hard making grafting a problem"; an ornamental plant (pp. 16–17); in Table 2 no fire blight or scab observed, in Table 3 mature on 9-15, 1¼ inches and red all over (pp. 10–11).
Experiments in Plant Heredity, Bulletin 237, p. 4, N. E. Hansen, Agricultural Experiment Station, South Dakota State College, Brookings; Open PRAIRIE, South Dakota State University, 1929-04. Supports: under "Pyrus baccata x P. Malus": "Some of the best crabs, like my Dolgo, are direct importations from Russia. The pedigree is not known."; Alexis, "very similar in every respect to Dolgo", grown from seed of Pyrus baccata from the Botanical Garden at Leningrad.
A Long While: An Ode to our Venerable Dolgo, Alexander Lavrisha, Secrest Arboretum newsletter (Fall 2024), The Ohio State University, 2024. Supports: a "Superior" rating for apple scab ("less than 5% of leaves affected and no aesthetic impact") in evaluations by the International Ornamental Crabapple Society; cold-hardy, valuable on its own and as a rootstock; white flowers; most conspicuous in late summer for its heavy crop; "a first-rate choice for cider and a very fine choice for apple butter"; seed of Malus × robusta, a hybrid of Malus baccata and Malus prunifolia, collected by N. E. Hansen at the Imperial Botanical Gardens in St Petersburg, 1897, and the variety introduced twenty years later; the name from the Russian Долго, translated "long" (of the fruit) or "a long while".
Ploidy determination, Malus (study MALUS.PLOIDYDETERMINATION.2008), USDA Agricultural Research Service, GRIN-Global, 2008. Supports: Dolgo (PI 588870) diploid (2x), by flow cytometry.