Dunstan Citrumelo

Dunstan Citrumelo is traditionally described as a grapefruit × trifoliate-orange hybrid and is grown for cold tolerance and grapefruit-like fruit. Accounts under the Dunstan name include seed-derived plants and cuttings from seedling stock; the sources do not establish that these are one authenticated original accession.^⁠[6]⁠[7]

Fruit reports vary by sample. One grower says fruits are usually fully yellow by late November; this is an external-color observation, not evidence of internal maturity. Tasting reports describe juicy, often seedy fruit with grapefruit or pummelo notes. Some tasters report little bitterness; others notice a pine-like aftertaste. Reported soluble-solids values include 9 °Brix in a 2023 Mulberries tasting and 10 °Brix in Ilya11’s 2019 first crop; a separate Mulberries chart lists 7–9 °Bx. These are separate published reports, not a controlled comparison.^{⁠[5]⁠[4]⁠[7]⁠[10]⁠[8]⁠[12]}

Mature trees have been reported to recover from severe defoliation and resume fruiting. Tom McClendon reports no permanent injury at approximately 10°F (Fahrenheit inferred from the U.S. growing context; the speaker says degrees without naming the scale), while an Olympia grower reported some branch loss around 9°F. These source-specific experiences do not establish a universal minimum.^⁠[9]⁠[1]