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Publication #FPS-604

Viburnum obovatum Walter Viburnum, Blackhaw1

Edward F. Gilman2

Introduction

Walter viburnum, in the opinion of some nursery growers, is the very best viburnum for use in central and south Florida. Unfortunately, it is not widely available. It is a shrub or small tree that can grow to a height of about 25 feet. However, there are forms of this plant that are upright, spreading, weeping or dwarf. It is difficult to determine which form you are buying by simply looking at the plant. The only way to determine the ultimate height and shape of the plant is to know the original source of the plant material. A reputable nursery will know the characteristics of their plants. The evergreen leaves of walter viburnum vary from very small to medium sized, glossy, leathery, and dark green. They are also fragrant when crushed. The winter or spring flowers occur in small, convex cymes held at the branch tips before new growth emerges. Flowers can cover the plant with white blooms for about 2 or three weeks. The fruits of this plant are small drupes that turn from red to black during maturation.

General Information

Scientific name: Viburnum obovatum
Pronunciation: vye-BER-num ah-boe-VAY-tum
Common name(s): Walter viburnum, blackhaw
Family: Caprifoliaceae
Plant type: tree
USDA hardiness zones: 7 through 10 (Fig. 1)
Figure 1. 

Shaded area represents potential planting range.


[Click thumbnail to enlarge.]
Planting month for zone 7: year round
Planting month for zone 8: year round
Planting month for zone 9: year round
Planting month for zone 10: year round
Origin: native to Florida
Uses: espalier; superior hedge; recommended for buffer strips around parking lots or for median strip plantings in the highway; screen; border; attracts butterflies; residential street tree; small parking lot islands (< 100 square feet in size); medium-sized parking lot islands (100-200 square feet in size); large parking lot islands (> 200 square feet in size)
Availability: somewhat available, may have to go out of the region to find the plant

Description

Height: 8 to 25 feet
Spread: 6 to 10 feet
Plant habit: oval
Plant density: dense
Growth rate: moderate
Texture: fine

Foliage

Leaf arrangement: opposite/subopposite
Leaf type: simple
Leaf margin: revolute; serrate
Leaf shape: obovate
Leaf venation: pinnate
Leaf type and persistence: evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no fall color change
Fall characteristic: not showy

Flower

Flower color: white
Flower characteristic: spring flowering

Fruit

Fruit shape: oval
Fruit length: less than .5 inch
Fruit cover: fleshy
Fruit color: black
Fruit characteristic: attracts birds

Trunk and Branches

Trunk/bark/branches: typically multi-trunked or clumping stems; no thorns; not particularly showy
Current year stem/twig color: gray/silver
Current year stem/twig thickness: thin

Culture

Light requirement: plant grows in part shade/part sun
Soil tolerances: occasionally wet; acidic; alkaline; sand; loam; clay
Drought tolerance: high
Soil salt tolerances: poor
Plant spacing: 36 to 60 inches

Other

Roots: usually not a problem
Winter interest: no special winter interest
Outstanding plant: not particularly outstanding
Invasive potential: not known to be invasive
Pest resistance: long-term health usually not affected by pests

Use and Management

Walter viburnum may be utilized in the landscape as a fine-textured, clipped hedge or tall screen. Small leaves make it a great candidate for shearing into a topiary, espalier or formal hedge. Older specimens can be trained into small trees with several trunks. Nurseries can also train young plants to grow in this manner.
Walter viburnum will grow well in a site that receives full sun or shade. It is native to acidic wetland forests that are frequently inundated for a period of time during the year, but it tolerates a broad range of growing conditions including moderate drought.

Pests and Diseases

No pests or diseases are of major concern.

Footnotes

1.

This document is FPS-604, one of a series of the Environmental Horticulture, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 1999. Revised May 2007. Reviewed June 2011. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Edward F. Gilman, professor, Environmental Horticulture Department, Teresa Howe, coordinator - Research Programs/Services, Gulf Coast REC, Bradenton, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 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.