White mulberry (Morus alba 'Unryu')

Overview

Morus alba ‘Unryu’, commonly known as Contorted White mulberry, is highly valued in ornamental landscapes for its dramatic, gnarled, and zigzag branching structure. This cultivar provides exceptional winter interest once its glossy leaves drop, making it a striking specimen plant. While the parent species, White mulberry, has a rich history tied to silk production, this unique variety offers textural appeal in modern gardens.

This deciduous tree typically remains compact, often taking on a shrub-like habit when pruned, reaching 8 to 15 feet tall and wide. It is a fast-growing introduction that adapts well to various conditions once established. The Morus alba ‘Unryu’ brightens the landscape with its unusual form, even though its spring flowers and subsequent edible fruits are less prominently featured than its structure.

Gardeners appreciate the resilience of this variety, which handles heat and mild drought once established. Its unique visual impact stems primarily from its habit, reflected in its Japanese cultivar name, ‘Unryu’, meaning twisted or contorted. Plan its placement carefully to showcase its distinctive silhouette throughout the dormant season.

Fast Facts

• Plant Family: Moraceae
• Plant Type: Tree
• Hardiness Zones: USDA Zones 4-8
• Size at Maturity:
  • Height: 8-15 ft
  • Spread: 6-12 ft
• Bloom Time: April to June
• Bloom Description: Greenish-white
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

The best planting time for Morus alba ‘Unryu’ is typically in the fall or early spring when the tree is dormant. Locate your White mulberry in a spot receiving full sun for the best overall development, although it tolerates light shade. This plant thrives in rich, moist, well-drained soils but is adaptable, tolerating alkaline soils.

Water usage is medium; ensure consistent moisture during the first year establishment. Since this tree is shallow-rooted, avoid deep cultivation nearby. Pruning is essential for managing shape and size; perform any significant structural cuts in late fall or winter to prevent excessive sap bleeding common to mulberries.

The Morus alba ‘Unryu’ exhibits good tolerance to drought once mature, making it a relatively low-fuss option for sunny areas needing structure. Monitor for common issues, although it generally avoids severe disease problems. Exposure to air pollution is also high, making it suited for urban planting sites.

Landscape Uses

The highly textural and contorted branching of Morus alba ‘Unryu’ makes it an exceptional focal point. It works perfectly as a specimen planting where its winter silhouette can be fully admired against a contrasting backdrop, such as a plain wall or evergreen screen. Its compact, shrub-like form, enhanced by pruning, lends itself well to smaller gardens or Asian-inspired designs.

Consider planting Morus alba ‘Unryu’ in small groups to amplify the dramatic effect of the twisted branches. For year-round interest, pair it with low-growing, evergreen groundcovers that won’t compete visually with its stark winter lines. Gardeners looking for materials for dried arrangements can utilize the unique stems cut during winter pruning.

Standout Features

Flower Qualities

• Insignificant

Fruit Qualities

• Showy
• Edible

Noteworthy Characteristics

Morus alba, commonly called white mulberry, is native to China and is renowned historically for being the primary foliage for silkworms. The ‘Unryu’ cultivar specifically features gnarled, zigzag branching, which is its most unique asset, contrasting sharply with the standard, wide-spreading habit of the species. While the species can produce large fruits, fruiting on the Morus alba ‘Unryu’ cultivar is usually quite sparse, allowing its architectural form to remain the main showpiece.

Tolerances

• Drought
• Air Pollution

Potential Problems

White mulberry generally resists major insect or disease outbreaks, but specific vigilance is required. Borers can attack trees, particularly in southern climates, so ensure the tree remains healthy to resist entry. You might occasionally observe whiteflies massing on the foliage during warm spells.

For disease control, watch for bacterial blight, which can cause foliage or branch dieback, and coral spot cankers. Management involves promptly pruning out affected wood to keep the infection localized. Furthermore, while the fruits are edible, they can be messy if they drop onto patios or walkways, which gardeners should consider when siting the tree.

Frequently Asked Questions

What hardiness zones is White mulberry suitable for?

Morus alba ‘Unryu’ is an adaptable variety suitable for USDA Hardiness Zones 4 through 8.

How large does Morus alba ‘Unryu’ grow?

This specific cultivar is often maintained as a smaller shrub, generally reaching 8 to 15 feet in height with a spread between 6 and 12 feet.

What sun exposure does Morus alba ‘Unryu’ need?

For optimal growth and branch definition, this White mulberry variety performs best in full sun, though it tolerates partial shade.

When does Morus alba ‘Unryu’ bloom?

The inconspicuous flowers of this tree bloom relatively early, from April to June, appearing greenish-white before developing into sweet, edible fruits.

Conclusion

The Morus alba ‘Unryu’ stands out in the landscape due to its truly captivating, contorted branching structure, offering exceptional aesthetic value, especially in winter. This White mulberry cultivar successfully combines ornamental interest with strong drought tolerance, minimizing maintenance requirements. Before planting, confirm your local USDA Zone aligns with Zones 4-8 and select a sunny location to maximize the unique appeal of this distinctive specimen.

Companion Planting

When designing a space around your Morus alba ‘Unryu’, focus on plants that complement its strong architectural presence rather than competing with it. Given its preference for well-drained soil and full sun, consider pairing it with lower-growing, slow-growing Japanese maples (Acer palmatum cultivars) for textural contrast in color and form, especially those with finer leaves. Alternatively, underplanting with hardy, fine-textured evergreen grasses provides soft foreground texture that highlights the stark, bare branches of the contorted mulberry in winter.

Seasonal Care Calendar

Spring is the time for observing new growth and ensuring adequate moisture as the weather warms, although established trees handle dry spells well. Summer care primarily involves monitoring for any minor pest issues like scale or mites, and keeping the ground beneath the shallow roots clear of competition. Late fall is an important time for application of dormant oil if pest pressure was high, and delaying major pruning until true dormancy in late fall or winter prevents sap seepage.