Our primary references for cultivar information are Jim Gardiner’s (2000) ‘Magnolias: a Gardener’s Guide’ and Matt Lobdell’s (2021) register of cultivars for Magnolia Society International. Further references are cited where relevant. Other important accounts of cultivars include Dorothy Callaway’s (1994) ‘The World of Magnolias’ and (in German) Beet Heerdegen and Reto Eisenhut’s (2020) ‘Magnolien und Tulpenbäume: Magnoliaceae’. Magnolia Society International’s journal ‘Magnolia’ is an ongoing trove of information.
M. kobus × M. salicifolia
Synonyms / alternative names
Magnolia × kewensis hort. ex Pearce
Magnolia salicifolia 'Kewensis'
RHS Hardiness Rating: H6
USDA Hardiness Zone: 5-9
Flowers precocious (late March to late April in S England), opening flat to 12 cm across, slightly nodding, fragrant; 6 inner tepals pure white, 3 outer ones small and sepaloid. Leaves resembling those of M. kobus; young stems lemon-scented when rubbed. A broad, small to medium tree, reliably floriferous. A self-sown seedling found in 1938 at RBG Kew, in the vicinity of the parents (Bean 1981). The original tree (now lost) had reached 11 m × 119 cm by 1981 (The Tree Register 2022).
The nothospecific name M. × kewensis was first used for this plant, but was published without a Latin description and is thus invalid (Lobdell 2021; IPNI 2022). Steven Spongberg’s (1976 etc) contention that it is a form of M. salicifolia seems today to be a minority view, although followed by Edwards & Marshall (2019).
(M. × veitchii) × (M. × soulangeana)
RHS Hardiness Rating: H5
USDA Hardiness Zone: 7-9
Flowers precocious but relatively late, cup-shaped, to 25 cm across; tepals deep magneta outside, inside white with a magenta basal stain; a spectacular contrast. A vigorous, upright, multistemmed large shrub or small tree, a Gresham hybrid named by Carl Ferris Miller (Chollipo Arboretum, Korea) at Ken Durio’s Louisiana Nursery before 2000. The identity of the M. × soulangeana parent is usually given as ‘Lennei’, but this might be an error for ‘Lennei Alba’ (Lobdell 2021). Kunso Kim (later Curator of The Morton Arboretum) worked at Chollipo. Williams, Gardiner & Gallagher (2016) highlight it as an up-and-coming cultivar in Europe.