Viburnum odoratissimum var. awabuki: Awabuki Sweet Viburnum

Edward F. Gilman, Dennis G. Watson, Ryan W. Klein, Andrew K. Koeser, Deborah R. Hilbert, and Drew C. McLean


Introduction

Large, leathery, medium to light green, highly lustrous leaves and clusters of extremely fragrant, small, white flowers, completely covering the plant in springtime, make Awabuki sweet viburnum a plant with great potential. The shiny leaves are quite distinctive from the dull, dark green, blunt-tip leaves of the species. For some reason, the species has fallen out of favor as a small tree in recent years, but it is often used as a screen or clipped hedge. Its dense, spreading, evergreen habit makes sweet viburnum suitable for use as a small tree, reaching only about 15 to 20 feet at maturity, with an open, multibranched, rounded canopy. The flowers are often followed by small, showy red berries which are highly ornamental and turn black when ripe. This is a small tree which should be tried, and some nursery operators are beginning to grow it. Thirty-year-old plants grow to about 18 feet tall and wide.

Figure 1. Full Form - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum
Figure 1.  Full Form - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum

General Information

Scientific name: Viburnum odoratissimum var. awabuki

Pronunciation: vye-BER-num oh-duh-ruh-TISS-ih-mum variety aw-wah-BOO-kee

Common name(s): Awabuki sweet viburnum

Family: Adoxaceae

USDA hardiness zones: 9A through 11 (Figure 2)

Origin: Taiwan and Japan

UF/IFAS Invasive Assessment Status: not considered a problem species at this time, may be recommended

Uses: screen; hedge; specimen; deck or patio; street without sidewalk; container or planter; sidewalk cutout (tree pit); tree lawn 3–4 feet wide; tree lawn 4–6 feet wide; tree lawn > 6 ft wide; highway median; parking lot island < 100 sq ft; parking lot island 100–200 sq ft; parking lot island > 200 sq ft

Figure 2. Range
Figure 2.  Range

Description

Height: 15 to 20 feet

Spread: 15 to 20 feet

Crown uniformity: symmetrical

Crown shape: round

Crown density: dense

Growth rate: slow

Texture: coarse

Foliage

Leaf arrangement: opposite/subopposite

Leaf type: simple

Leaf margin: serrate

Leaf shape: elliptic (oval)

Leaf venation: pinnate, bowed, brachidodrome

Leaf type and persistence: broadleaf evergreen, evergreen

Leaf blade length: 3 to 6 inches

Leaf color: dark green wax, thick, and shiny on top, paler green and smooth underneath

Fall color: no color change

Fall characteristic: not showy

Figure 3. Leaf - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum
Figure 3.  Leaf - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum

Flower

Flower color: white/cream/gray

Flower characteristics: showy; funnel shaped; emerges in clusters on cymes

Flowering: spring to summer

Figure 4. Flower - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum
Figure 4.  Flower - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum

Fruit

Fruit shape: round

Fruit length: less than .5 inch

Fruit covering: fleshy drupes

Fruit color: red, black

Fruit characteristics: attracts birds; showy; fruit/leaves not a litter problem

Trunk and Branches

Trunk/branches: branches droop; not showy; typically multi-trunked; no thorns

Bark: green and reddish, becoming brownish gray with age

Pruning requirement: needed for strong structure

Breakage: resistant

Current year twig color: green

Current year twig thickness: thick

Wood specific gravity: unknown

Figure 5. Bark - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum
Figure 5.  Bark - Viburnum odoratissimum var. awabuki: Awabuki sweet viburnum
Credit: Gitta Hasing

Culture

Light requirement: full sun, partial sun or partial shade

Soil tolerances: clay; sand; loam; alkaline; acidic; well-drained

Drought tolerance: moderate

Aerosol salt tolerance: unknown

Other

Roots: not a problem

Winter interest: no

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: susceptible

Pest resistance: resistant to pests/diseases

Use and Management

Sweet viburnum grows quickly in full sun or partial shade on a wide variety of soils. Relatively maintenance-free, sweet viburnum grown as a tree will require only occasional pruning to control size and shape. This would be a good tree for planting along a street where power lines or other obstructions limit overhead space.

The cultivar 'Emerald Lustre' has larger leaves and `Nanum' is a dwarf form.

Propagation is by cuttings or layerings.

Pests

This tree is usually free of pests.

Viburnum aphid is gray to dark green and feeds in clusters at the tips of the branches, causing leaf curl. The insects can be dislodged with high pressure water spray from the garden hose.

Inspect the stems of unhealthy-looking plants for possible scale infestations. If found, spray with horticultural oil for some control.

Caterpillars eat holes in the new foliage. This may be more troublesome in the nursery than in the landscape.

Thrips, mites, white-fly, bagworms, and sooty mold are also problems, but none are normally serious.

Diseases

Bacterial leafspot causes round, water-soaked spots on leaves and young stems. These develop into shrunken, brown areas about 1/8-inch in diameter. Destroy infected leaves.

Bacterial crown gall forms galls on the lower stems. Do not replant in the same spot.

Shoot blight causes grayish to brown decayed spots on the leaves. The spots first appear at the leaf margins, then spread to the rest of the leaf. Infected flower clusters or twigs are killed.

A number of fungi cause leaf spots. Rake up and destroy infected leaves.

Downy mildew and powdery mildew cause a white powdery growth on the leaves.

Reference

Koeser, A. K., Hasing, G., Friedman, M. H., and Irving, R. B. 2015. Trees: North & Central Florida. Gainesville: University of Florida Institute of Food and Agricultural Sciences.

Footnotes

1. This document is ENH817, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date November 1993. Revised December 2018. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.
2. Edward F. Gilman, professor emeritus, Environmental Horticulture Department; Dennis G. Watson, former associate professor, Agricultural Engineering Department; Ryan W. Klein, graduate assistant, Environmental Horticulture Department; Andrew K. Koeser, assistant professor, Environmental Horticulture Department, UF/IFAS Gulf Coast Research and Education Center; Deborah R. Hilbert, graduate assistant, Environmental Horticulture Department, GCREC; and Drew C. McLean, biological scientist, Environmental Horticulture Department, GCREC; UF/IFAS Extension, Gainesville, FL 32611.