Black haw (Viburnum prunifolium) is a hedge or short tree native to the United States. It is often grown for its attractive qualities. It produces small white flowers in late spring and in late summer and has a crop of red berries that turn nearly black in color, which tend to be extremely attractive visually and which also attract many species of birds. The berries are actually edible, and in some regions people make them into jams. Other parts of the black haw have been used in traditional medicine preparations.
For gardening purposes only, black haw tends to work well in areas where lowest winter temperature is no lower than -25 degrees F (-31.7 degrees C). It can be planted in diverse areas of the US, and zones suggested are between four to eight. The tree would likely prosper elsewhere in the world where temperature highs and lows are approximately similar to the US designated zones.
As a tree, black haw can get about 30 feet (9.14 m) in height, though this may take some time to accomplish. In shrub form, Viburnum may spread about six feet (1.83 m) and grow half as tall as tree height. This, again, could take a while and some careful pruning, to fully fill a space. Whether planted as shrub or tree, some attention must be paid to sun exposure, although a range of sun exposures may be permissible. Viburnum can usually tolerate up to partial shade, but will also thrive in full sun areas.
There is some logic to the traditional medicine use of black haw. Normally the bark is used and the tree has sometimes been called cramp bark. It does have chemicals with a close relationship to aspirin, and one way in which it was employed was to treat cramping during the menstrual cycle, or to calm the uterus at other times. Part of black haw’s unsavory past was its use on enslaved women to make certain they did not have miscarriages; more births increased slave population and the slave owner’s wealth. In other instances, though, concoctions made with the bark were voluntarily taken to treat a variety of feminine ills.
Today there is concern about the safety of black haw, because the aspirin like substance in it, salicin, may cause damage to the body and could be indicated in birth defects. Despite these concerns, as raised by the Food and Drug Administration (FDA) in the US, the product is still available in many natural food stores. Regulation of its sale is not within the province of the FDA, unless there exists legitimate proof of its danger. Nevertheless, pregnant women are duly warned that this product could be harmful if used during pregnancy, and children should not receive as it may run the same risks as aspirin and could possibly result in Reye’s syndrome.