In 1804, Americans introduced "sacred bamboo" as a garden ornament; it spread across an estimated 22,400 forest acres, and its berries have been linked to bird deaths

"Sacred bamboo" sounds harmless enough, but it isn't bamboo, nor is it sacred. It’s a flowering shrub called Nandina domestica that American gardeners have been growing for more than two centuries for its bright red berries and red winter foliage. A comprehensive review of the species by the U.S. Forest Service tells a more complex story. The review, part of the agency's Fire Effects Information System, traces how this 'pretty' plant escaped American gardens, spread into Southern forests and affected birds that eat its berries.

A Chinese import that charmed American gardens

Nandina is native to China, Japan, and India, the review notes. Nandina was introduced to the United States in the early 1800s; most university extension services and garden historians, including the University of Florida's IFAS Extension, cite 1804 as the exact year it was brought over as an ornamental. Americans loved it right away. It kept its leaves over the winter, and its foliage turned deep red in cold months. Nurseries sell it for the same reasons today. For decades, Nandina stayed largely confined to the gardens where it was planted before beginning to spread on its own into the wild.

How a garden shrub spread across 22,400 acres of forest

According to the review, birds eat nandina berries and carry the seeds as they fly in search of food. Those seeds drop into forests, take root, and grow into dense clumps that keep sunlight from the forest floor. This can eventually displace native plants that local wildlife depend on for food and shelter. The review cites U.S. Forest Inventory and Analysis data from forests in 12 southern states. Nandina was found growing naturally in nine of those twelve southern states, including Texas, Florida, Virginia, and Tennessee. The Forest Service estimates that nandina has overrun natural vegetation across about 22,414 acres of southern forest. Tennessee has the greatest share, with just more than 9,200 acres.

The berries carry more than color

Nandina's threat is not just the extent of its spread. It also concerns what's in its berries. A study conducted by veterinary pathologists from the University of Georgia, titled ‘Feeding Behavior-Related Toxicity due to Nandina domestica in Cedar Waxwings (Bombycilla cedrorum)’ looked into an unusual bird death and found that numerous cedar waxwings died in a Georgia garden in April 2009. Upon examination of five of the dead birds, researchers found nothing but nandina berries in their intestines. The birds' lungs, hearts, and other organs showed internal bleeding, according to the report, which indicated cyanide poisoning. The study also helps explain why cedar waxwings are vulnerable. These birds consume fruits in big gulps and in great numbers; it is said that one flock of them could clean a nandina plant in minutes. Researchers say this rapid eating may limit the birds' ability to process the cyanide compound.

Not every berry is equally dangerous

In a study titled 'Fruits of Nandina domestica are (Sometimes) Cyanogenic and (Sometimes) Hazardous to Birds' from the University of North Carolina at Chapel Hill's herbarium, published in 2022 in the journal Poisonous Plant Research, the nandina leaves and berries were tested monthly over a period of one full year. The study found green, unripe berries had the highest cyanide content and released it the fastest. Research shows that ripe red berries tend to be less cyanogenic, and their cyanide content may drop further the longer they remain on the plant. The same study suggests that most birds that peck at a berry or two may face comparatively less risk. The greater risk is to birds such as cedar waxwings that eat large quantities at one time, especially when the berries are green or just ripe.

What gardeners should know

Nandina is still sold widely in nurseries throughout the United States. It is a popular landscaping plant, especially in winter, because of its bright berries and low-maintenance nature. But its long history in America shows how an ornamental plant can spread beyond gardens and affect ecosystems.

Local extension or gardening services can help you choose the right replacement; options like winterberry holly and American beautyberry offer a similar look and tend to be less problematic. That’s a small but significant swap for a generation increasingly concerned about sustainable, pollinator-friendly gardening. Sometimes the most festive-looking plant on your porch can be the one that is quietly reshaping the woods a few miles away.