Magnolia × wieseneri
Common Name: magnolia
Type: Tree
Family: Magnoliaceae
Native Range: Garden origin
Zone: 6 to 9
Height: 15.00 to 25.00 feet
Spread: 12.00 to 20.00 feet
Bloom Time: May to September
Bloom Description: White with rose-crimson stamens
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Flowering Tree
Flower: Showy, Fragrant
Tolerate: Clay Soil

Culture

Best grown in moist, slightly acidic, organically rich, well-drained loams in full sun to part shade. Site in locations protected from strong winds, but avoid southern exposures in full sun close to houses where buds and foliage may be induced to open too early in spring. Plants appreciate consistent and regular moisture throughout the year, and are generally intolerant of soil extremes (dry or wet). Mulch root zone. Plants are difficult to transplant once established in the landscape.

Noteworthy Characteristics

The genus Magnolia consists of about 100 species (plus numerous additional hybrids and cultivars) of deciduous or evergreen trees and shrubs. Most plants feature large and simple leaves and showy, sometimes fragrant flowers (yellow, white, pink or purple) which bloom in early spring before or while the leaves are emerging or in late spring to summer when trees are fully leaved.

Magnolia x wieseneri, sometimes commonly called Watson’s magnolia, is a deciduous magnolia hybrid that typically matures to 15-25’ tall with a somewhat rounded growing habit. Parents of this hybrid are M. obovata and M. sieboldii. Ivory flowers (to 6-8” across) with showy rose-crimson stamens bloom May-June. Flowers are very fragrant. Each flower has 10-12 tepals. Obovate leaves (to 4-8” long) are medium green.

This hybrid originated in Japan in the 1800’s. Japanese exhibitors brought it to the World Exhibition in Paris in 1889 for display. Although this magnolia was subsequently named M. x watsonii in 1891 in England by Sir Joseph Dalton Hooker in honor of fellow Kew botanist William Watson, it was subsequently discovered that this magnolia had already been named M. x wieseneri about six months earlier by a French botanist in honor of the purchaser of the plant (Weisener) from a Japanese exhibitor at 1889 Paris exhibition. Although the first given name is accepted under rules of botanical nomenclature, this magnolia has retained the common name of Watson’s magnolia (from x watsonii) in many circles today.

Genus name honors Pierre Magnol, French botanist (1638-1715).

Specific epithet honors a Mr. Weisener who purchased the plant from a Japanese exhibitor at the 1889 Paris exhibition.

Problems

No serious insect or disease problems. Late frosts may damage flowers.

M. x wieseneri blooms later than many of the magnolias and its flowers are unlikely to suffer frost damage in spring.

Garden Uses

Excellent specimen or accent for sunny areas in the landscape where spring flowers can be appreciated. Small shade tree.