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Publication #ENH-538

Magnolia kobus: Kobus Magnolia1

Edward F. Gilman and Dennis G. Watson2

Introduction

A striking tree in summer or winter. Dropping its large, six-inch leaves in fall without any spectacular display of color, Kobus Magnolia forms an attractive winter specimen with its rounded silhouette and multiple trunks originating close to the ground. Supposedly grows 30 to 40 feet tall but is most often 25 feet or less in an open, sunny landscape site and is capable of reaching 75 feet in height in its native forest habitat. In an open site, spread is often greater than height with 25-foot-tall trees 35 feet wide if given the room to grow unobstructed. Branches gracefully touch the ground on older specimens as the tree spreads, in a manner not unlike open-grown Live Oaks. Allow plenty of room for proper development.

Figure 1. 

Mature Magnolia kobus: Kobus Magnolia


Credit:

Ed Gilman


[Click thumbnail to enlarge.]

General Information

Scientific name: Magnolia kobus
Pronunciation: mag-NO-lee-uh KOE-bus
Common name(s): Kobus Magnolia, Northern Japanese Magnolia
Family: Magnoliaceae
USDA hardiness zones: 5A through 8A (Fig. 2)
Origin: not native to North America
Uses: specimen; container or planter
Availability: somewhat available, may have to go out of the region to find the tree

Figure 2. 

Range


[Click thumbnail to enlarge.]

Description

Height: 25 to 30 feet
Spread: 25 to 35 feet
Crown uniformity: symmetrical
Crown shape: round, spreading
Crown density: dense
Growth rate: slow
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

Figure 3. 

Foliage


[Click thumbnail to enlarge.]

Flower

Flower color: white/cream/gray, pink
Flower characteristics: very showy

Fruit

Fruit shape: irregular, elongated
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 droop; not 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: sand; loam; clay; slightly alkaline; acidic; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: low

Other

Roots: not a problem
Winter interest: yes
Outstanding tree: yes
Invasive potential: little invasive potential
Ozone sensitivity: tolerant
Verticillium wilt susceptibility: susceptible
Pest resistance: free of serious pests and diseases

Use and Management

The lightly-fragrant blooms which appear in spring before the new leaves unfold are ivory-colored to pale pink and four inches in diameter. 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.

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.

The cultivar `Wada's Memory' has black-green leaves, large, six-inch blooms and an upright or columnar growth habit (at least in youth). 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.

Footnotes

1.

This document is ENH-538, one of a series of the Environmental Horticulture, UF/IFAS Extension. Original publication date November 1993. Revised October 1998. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Edward F. Gilman, professor, Environmental Horticulture Department; Dennis G. Watson, associate professor, Agricultural Engineering Department, UF/IFAS Extension, Gainesville FL 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.