The black haw viburnum (Viburnum prunifolium) is a species of viburnum shrub that can also be a small tree. It features abundant clusters of snowy white flowers in the spring that are followed by black fruit in the fall.
The scientific name for this shrub is Viburnum prunifolium and is part of the Adoxaceae family. It used to be included in the Caprifoliaceae (honeysuckle) family. The species name of prunifolium indicates that the leaves are similar to those of Prunus trees and shrubs, especially the plums.
Some of the names associated with this viburnum shrub species are black haw, stag bush, blackhaw viburnum, blackhaw or sweet haw. The name "haw" came about because it looks like a hawthorn, though those trees and shrubs are part of the Crataegus genus.
Preferred USDA Hardiness Zones
Viburnum prunifolium will be able to grow in Zones 3 to 9. It is native to the eastern and midwestern United States.
Size & Shape
Once it has reached its mature size, this shrub will be 12' to 15' tall and 6' to 12' wide. It forms a round shape.
Choose a site for your black haw that will provide full sun to partial shade It can also handle a spot with more shade, though there may be fewer flowers and fruit.
The leaves look like those on plum trees, as noted by the species name of prunifolium. They are dark green, 1" to 4" long and are elliptical or ovate in shape. In the fall, the foliage will transform into shades of red and purple.
The white flowers form in clusters called cymes. They appear in the spring and make the shrub very attractive.
After the flowers are fertilized and fade away, black fruits are known as drupes form and ripen by fall. They are edible for both humans and wildlife. You can cook them for use in preserves and jams or eat them fresh.
Butterflies, bees, and birds are all attracted to this shrub.
You can use this as part of a drought tolerant landscape. It is also able to withstand pollution in urban settings.
Black haw viburnum is able to tolerate the juglone produced by the black walnut and other walnut tree species. This substance is allelopathic and will harm many other plants, so this is a great choice to plant nearby.
If you want a shrub with leaves that are red when they first appear and again in the fall, look for 'Ovazam', 'Forest Rouge', 'Summer Magic' or 'Early Red'.
Distinctive features of this shrub include the bark, which resembles alligator skin, and the fishbone pattern formed by the branches.
Good drainage is needed for this shrub. It can tolerate a range of pH levels.
You can propagate Viburnum prunifolium by germinating the seeds or taking cuttings from an existing shrub.
You can make a black haw viburnum into a small tree through pruning to create a central leader. It can also be trained into an informal hedge for use as a privacy screen. Viburnum prunifolium may sometimes clone itself through suckers that will need to be removed it keep it under control.
Any pruning should be done right after flowering has finished so you do not accidentally remove the buds for the next year's blooms.
There are not usually many pest problems found on this shrub. You may see:
- Aphids may cluster on your black haw. You can simply shoot jets of water at them or use an insecticidal soap or horticultural oil. The latter two treatments should be used only on cooler days so the leaves of the shrub do not get burned. You should also control any ants in the area as they will care for the aphids in exchange for their honeydew.
- Borers will attack the trunk by burrowing through the bark to the inner layers. It may be difficult to get rid of the beetles and if the damage is widespread it can lead to the death of the shrub.
- Scales will suck the sap out of the stems. Horticultural oil can be used on cool days to help fight the infestation.
- Branches with cankers should be pruned out while they are still small. If they are large you may eventually need to take out the whole shrub.
- Dieback happens when parts of the plant start to wither and the damage spreads throughout the entire shrub over time.
- Gray mold.
- Powdery mildew can be treated with organic methods like a baking soda solution, water spray or neem.
- Verticillium wilt.
According to Henrietta's Herbal, black haw viburnum has uses in gynecology for various conditions, like problems with menses and uterine irritability. It also has been used to treat diarrhea and heart palpitations, among other illnesses. Note: This section is not intended as medical advice and you should consult a health professional before you use Viburnum prunifolium.