Question: Recently, the Master Gardener Plant Clinic received an email from someone who has an invasive plant sprouting up in her backyard. Along with sending a photo of the plant, she asked us to identify it and how to get rid of it!
Answer: The shrub invading her space is called Nandina (Nandina domestica), and also goes by the dubious name Heavenly Bamboo — in some cases, it’s not so heavenly!
Nandina is not bamboo (it’s classified in the family Berberidaceae) but gets it’s common name because of its unique stems resembling bamboo shoots up close. It’s native in Japan and even into the Himalayas in China, introduced to America in 1804 as an ornamental.
Nandina is an evergreen shrub, popular with landscapers because it is tough as nails, very drought hardy, grows in shade as well as full sun and has pretty green foliage that turns a deep maroon in winter, depending on the variety.
It also sports lovely white fragrant flowers in May-June on long terminal panicles followed by bright red berries that persist all winter long. It’s relatively pest and disease-free and deer seem to leave it alone.
So what’s not to like?
Unless you want to plant it as an informal hedge in a shrub border or as a mass grouping, you may want to reconsider using common Nandina in your landscape. Not only does it spread by seed, but also by rhizomatous underground stems, so it tends to spread vigorously. Nandina has been classified as an invasive plant in the South, where it has spread to outcompete native plants.
Leaves and berries are toxic to livestock and other domestic animals. The berries contain cyanide and can cause bird mortality if consumed in large quantities. Cedar waxwings and robins will eat the berries when other food sources are unavailable. For this reason, and to help manage spread, it’s important to never let your Nandina form berries.
As soon as the flowers fade, clip them off. If you find berries, dispose of them in garbage bags and take them to the landfill, not your compost pile.
If you have Nandina and wish to remove it, you will need to be persistent. Dig the plants up as best you can, getting as much of the root and rhizome system as possible. New plants will sprout even from fragments of roots and rhizome, so that’s where persistence comes into play.
As new sprouts emerge, dig them up or spot treat with glysophate or triclopyr using a 1% solution with .25% surfactant. Eventually the plant will drain its resources and give up, but it may take awhile.
The good news is there are lots of cultivars that don’t have the nasty characteristics mentioned above. Look for cultivars that are fruitless or don’t tend to spread. There are many alternatives to consider which are just as attractive and yet easy to manage.
Atropurpurea Nana is one of the older cultivars. It’s form is a tight globe, 2 feet by 2 feet and has foliage that is yellow-green tipped with red during the growing season, turning to deep red in the winter.
Another in this class is Wood’s Dwarf. Others include Gulf Stream, Moon Bay, Plum Passion, Lemon Lime and Flirt.
Firepower is a dwarf cultivar from New Zealand noted for its lime green leaves and superior red winter color. Chirimen (Nandina domestica filamentosa ‘Chirimen’) has unusual threadlike foliage.
With any invasive plant, it’s important to be a responsible gardener. By keeping a close eye on your Nandina and performing regular renewal pruning in the spring each year by removing the larger stems to the ground, clipping off flowers and berries, you can keep it under control.
Otherwise, remove and replace.