It can be fun to try new plants and shrubs in the yard. And every now and then, a particular plant becomes popular and is widely introduced into an area where it’s not native. At times, the newcomer settles in well and simply adds to the landscape. Other times, however, a non-native plant can cause trouble. Often, because it has no natural ‘enemies’ in the environment it can be invasive or difficult to control. Occasionally, the introduced plant does far more harm by actually poisoning native wildlife.
Such is the case with a plant recently brought to the attention of the Tualatin Soil and Water Conservation District (SWCD) by Dana Sanchez, Oregon State University Extension wildlife specialist, who reports that a common landscaping shrub may threaten local bird populations due to its toxic berry.
The shrub is commonly known as nandina, sacred bamboo, or heavenly bamboo. Nandina is found in the landscaping of yards, parks, hospital grounds, and other locations across the lower 48 states. Planted for its bright red berries and contrasting dark green foliage, the shrub adds color and texture in residential and commercial landscapes.
Some homeowners planted nandina with the intention of providing food for cedar waxwing, American robin, northern mockingbird, and other birds that depend on winter fruits to survive. Nandina berries stay on the bush for months, attracting hungry birds when food is in short supply.
And that can be a major problem for the birds. When dozens of cedar waxwings were found dead in Georgia three years ago, investigators at the University of Georgia found the cause to be nandina berries. Bird autopsies revealed the berries lodged in the birds’ crops, as well as hemorrhaging of several internal organs.
The root of the birds’ distress is the cyanide and other alkaloids contained in the berries that produce highly toxic hydrogen cyanide, which is extremely poisonous to all animals. Sudden death may be the only sign of cyanide poisoning and death usually comes within minutes to an hour of exposure.
Worse still, nandina is a non-domestic, noxious, and highly invasive weed that displaces the non-toxic, native plants on which local birds normally thrive. Nandina has been imported from China and Japan, and has invaded many natural areas. Homeowners and commercial landscapers are still planting this toxic species, unaware of the risk.
“Over 220 bird species nationwide are in serious decline, including our most common birds. Birds are being killed on all fronts,” said Jerry W. Davis, a certified wildlife biologist from Arkansas. “By working together, we can eliminate this toxic and noxious invasive plant. If you are not doing your part, the job is not getting done.”
Consider these simple steps to help reduce and eventually remove the presence of nandina in the local landscape:
1. Avoid using nandina in landscaping projects and opt for beneficial native plants with a similar appearance, such as Pacific ninebark, red elderberry or red huckleberry.
2. If you have nandina already and aren’t ready to part with it, take care to prune the bushes to remove the berries as winter approaches. Planting a variety of non-toxic food sources such as serviceberry, snowbush, or red twig dogwood will help fill the gap.
3. Currently, there are no control efforts underway in Washington County for nandina, but sharing this article with the landscaping company that handles your home or business may help. And report sightings to the Invasive Species hotline at oregoninvasiveshotline.org.
For more information on identifying invasive plants, or learning about native plants for your landscape, see the SWCD website or contact the SWCD at 503-648-3174.
-- Jennifer Nelson, Tualatin SWCD