Morus alba 'Unryu'
Common Name: white mulberry
Type: Tree
Family: Moraceae
Zone: 4 to 8
Height: 8.00 to 15.00 feet
Spread: 6.00 to 12.00 feet
Bloom Time: April to June
Bloom Description: Greenish-white
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Insignificant
Leaf: Good Fall
Attracts: Birds, Butterflies
Fruit: Showy, Edible
Other: Winter Interest
Tolerate: Drought, Air Pollution

Culture

Best grown in rich, moist, well-drained soils in full sun to part shade. Best in full sun. Prune in late fall or winter to avoid bleeding. Tolerates heat, drought and a somewhat wide range of soils, including alkaline ones. Shallow rooted.

Noteworthy Characteristics

Morus alba, commonly called white mulberry is native to China. It is a rounded, fast-growing, deciduous tree that typically grows to 30-50’ tall and as wide. It usually develops a wide-spreading crown with age. The leaves of this tree have been used in China since at least 2600 B.C. as the primary diet for silkworms used to make silk. Trees were introduced into North America in colonial times in an effort to establish a silk industry. Although the industry never took hold, the trees did take hold and have over time escaped cultivation and naturalized in fields, waste areas, forest margins and along roads throughout much of the U.S. This tree has also been planted in various areas for erosion control and windbreaks. White mulberry is usually dioecious (separate male and female trees), but sometimes is monoecious. Small yellowish-green flowers in drooping catkins bloom in spring (March-April). Fertilized flowers on female trees are followed by sweet, edible blackberry-like fruits (cylindrical drupes to 1” long) that mature in June. Fruits ripen to white or pink, but sometimes to darker reds or purple-blacks. Fruits are loved by birds. Glossy, rounded, usually 2-3 lobed (but sometimes unlobed), dark green leaves (to 8” long) have serrate margins and uneven (sometimes cordate) bases. Glossy leaf surfaces distinguish this tree from red mulberry. Fall color is an unattractive yellow (sometimes green, yellow and brown).

Genus name comes from the Latin name.

Specific epithet comes from the Latin word meaning white in reference to fruit color.

‘Unryu’, sometimes commonly called contorted mulberry, is a cultivar that features gnarled, contorted, zigzag branching on a tree that can reach 30-40' tall but most often grows or is maintained via pruning as a much smaller shrub to 8-15' tall. Inconspicuous spring flowers bloom April - June in catkins. Flowers are followed by small edible sweet purple fruits (July to September). Fruiting for this cultivar is usually quite sparse. Glossy light green leaves (to 7" long) produce often-attractive yellow fall color. However, it is the unusual twisted branching that makes this plant unique. Unryu in Japanese means twisted or contorted. Some confusion currently exists regarding the proper botanical name for this plant.

Cultivar name is often listed as 'Unryu' or 'Tortulosa' under Morus bombycis, Morus alba or Morus australis.

Problems

No serious insect or disease problems. Borers may be a problem particular in the South. Whiteflies mass on some trees. Bacterial blight may kill foliage/branches. Coral spot cankers may cause twig dieback. Bacterial leaf scorch, powdery mildew and root rot may also occur. Watch for scale, mites and mealybugs. Messy fruit may be a concern.

Garden Uses

Contorted branching in compact versions of this shrub makes an unusual but attractive addition (specimen or small groups) to Japanese gardens. After leaf drop in fall, the contorted stems add excellent winter interest to the landscape. Stems may be added to floral arrangements.