Cultivar 487: Kerr

Kerr is a prairie apple crab from a Dolgo x Haralson cross developed at Morden, Manitoba, and linked to W. L. Kerr. Sources consistently place it in 1952. They also note the cross was made in 1938 and later tested as Morden 352 before introduction. It was widely recommended for prairie planting, including as a cultivar highly recommended for most of the prairie region and for all Prairie Provinces in later guidance. [S1] [S3] [S4] [S6]

The fruit is small for an apple but large for a crab, usually about 4 to 4.5 cm across. Descriptions range from dark red or purple red to nearly black when fully ripe, often with heavy bloom. The flesh is yellow to creamy yellow and is sometimes tinged or flecked with red. Several sources describe it as crisp, very juicy, and sweet tart, with quality good enough for fresh eating, especially after some storage. It also excels for jelly, canning, juicing, and general processing. One older prairie description called it a large Dolgo, but milder in flavor. [S3] [S4] [S6] [S7] [S8]

Kerr ripens late, usually in late September into early October. It is repeatedly described as a good keeper. Several sources say it stores until early January, and one later note reports storage potential up to 27 weeks. Prairie recommendation lists also mark it as a late season preserving fruit. One source notes that the fruit is frost resistant, can hang through very late frosts, and does not drop readily. [S1] [S3] [S6] [S7]

The tree is described as moderately vigorous to fair in vigor, broadly upright to round headed, with strong, wide angled branches and annual productivity. That branch structure made it notable beyond fruit quality. Prairie production guidance singled Kerr out as a promising hardy semi vigorous stembuilder for topworking. Sources also describe it as ornamental as well as useful. [S3] [S6]

Hardiness evidence varies in wording but is clear in prairie intent. Saskatchewan tables rate Kerr as hardy, and one profile summarizes it as hardy to Zone 3. Other prairie recommendation systems place it around H2 or H2-3, and a Saskatchewan note says it is apparently hardy in Zones 3B and 4. At the same time, some records report dieback to the snow line or moderate to severe injury in colder or exposed sites. The best reading is that Kerr was valued as a hardy prairie apple crab, but not among the very hardest types in all places. [S1] [S5] [S6] [S7] [S8]

Kerr also sits in an important prairie breeding line. With Dolgo as one parent and Haralson as the other, it bridges crabapple hardiness and more apple-like eating quality. Later prairie literature used it as a clear example of size improvement in hardy prairie apple crab breeding. That helps explain its long presence in recommendation lists, nursery availability, and prairie cultivar summaries. [S2] [S3] [S4] [S6]

A few details remain unsettled. Sources differ slightly on whether Kerr is best framed as a crabapple, apple crab, or crabapple derived apple, though all agree it belongs to the small fruited hardy Malus group. Fire blight ratings also conflict. Later Saskatchewan tables place it under good resistance, while an older Saskatchewan comparison table listed it as susceptible. [S1] [S5] [S6] [S7] [S8]

Summary source basis

• S1: Edible Apples in Prairie Canada
• S2: Nursery Plants Available from South Dakota Nurseries
• S3: Tree fruit production for the Prairie Provinces
• S4: An index of fruit cultivars tested or developed on the Canadian prairies.
• S5: HortFactsAppleCultivars CStushnoff 1985
• S6: Kerr
• S7: hortfacts_1976_3.pdf
• S8: hortfacts stushnoff

This summary currently draws chiefly from Edible Apples in Prairie Canada, with 7 additional supporting sources linked below.

Featured source descriptions

“Flesh yellowish, flecked with dark red.”
— ^[1]

“Listed with hardiness/class code CR.”
— ^[1]

“Fruit frost resistant.”
— ^[1]

“H2-3 hardiness rating.”
— ^[1]

Direct parent cultivars

• No direct linked parent cultivars promoted yet.

Parentage claim text

• Dolgo x Haralson.
• Kerr is given as a cross of Dolgo x Haralson.
• 'Dolgo' x 'Haralson'.
• Parentage: Dolgo x Haralson.

Derived or downstream cultivar links

• No derived or downstream lineage links yet.

Source-story quotations

• Kerr (Dolgo x Haralson) W.L.Kerr, Morden (1952) CREdible Apples in Prairie Canada, p40
• Kerr (Dolgo x Haralson) W.L.Kerr, Morden (1952) CREdible Apples in Prairie Canada, p40
• Kerr (Dolgo x Haralson) W.L.Kerr, Morden (1952) CREdible Apples in Prairie Canada, p40
• Kerr (Dolgo x Haralson) W.L.Kerr, Morden (1952) CREdible Apples in Prairie Canada, p40

Taxonomy context: No family-tree context surfaced yet.

Related cultivars mentioned in source context