Introduction
A striking tree in summer or winter. The cultivar `Wada's Memory' has black-green leaves, large, six-inch, fragrant white blooms which appear before the leaves, and an upright or columnar growth habit (at least in youth). Dropping its large, six-inch leaves in fall with a yellow display of color, `Wada's Memory' forms an attractive dark green winter specimen. Young trees flower poorly. The pink fruits which develop split open to reveal bright red seeds, which sway from slender threads before dropping to the ground.
Credit: Ed Gilman
General Information
Scientific name: Magnolia kobus
Pronunciation: mag-NO-lee-uh KOE-bus
Common name(s): 'Wada's Memory' Kobus Magnolia, `Wada's Memory' Northern Japanese Magnolia
Family: Magnoliaceae
USDA hardiness zones: 5A through 8A (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: specimen; street without sidewalk; screen; container or planter; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; sidewalk cutout (tree pit)
Availability: somewhat available, may have to go out of the region to find the tree
Description
Height: 25 to 30 feet
Spread: 25 to 35 feet
Crown uniformity: symmetrical
Crown shape: upright/erect, oval, pyramidal
Crown density: dense
Growth rate: moderate
Texture: coarse
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: entire, undulate
Leaf shape: obovate, elliptic (oval)
Leaf venation: brachidodrome, pinnate
Leaf type and persistence: deciduous
Leaf blade length: 4 to 8 inches
Leaf color: green
Fall color: yellow
Fall characteristic: showy
Flower
Flower color: white/cream/gray, pink
Flower characteristics: very showy
Fruit
Fruit shape: elongated, irregular
Fruit length: 1 to 3 inches
Fruit covering: dry or hard
Fruit color: pink, red
Fruit characteristics: attracts birds; showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches don't droop; showy; typically multi-trunked; thorns
Pruning requirement: little required
Breakage: resistant
Current year twig color: green, brown
Current year twig thickness: medium, thick
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; acidic; slightly alkaline; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: unknown
Other
Roots: not a problem
Winter interest: yes
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: susceptible
Pest resistance: free of serious pests and diseases
Use and Management
Kobus Magnolia should be grown in full sun or partial shade on any well-drained soil. Probably not for poorly-drained areas but supposedly tolerant of soil with an alkaline pH. It appears to grow well in clay soil. It will be available at selected nurseries.
Propagation is easily done by cuttings.
Pests and Diseases
No pests or diseases are of major concern but occasionally bothered by scale as are other Magnolias.
