Low maintenance and hardy, with showy flowers and beautiful winter fruit, heavenly bamboo (Nandina domestica) is a favorite in ornamental gardening. Although it isn’t usually afflicted with pests or diseases, it does have a few susceptibilities. Knowing how to recognize them can increase your chances of growing healthy heavenly bamboo.
Native to Asia from India to Japan, heavenly bamboo is not actually a species of bamboo at all. It is a deciduous shrub with a rhizomatous habit, and produces spectacular white flowers in June, followed by clusters of bright red berries that persist from fall through spring. It is winter hardy to U.S. Department of Agriculture plant hardiness zones 6 through 10, although it may grow better in the smaller range of 7 through 9.
Multiple viruses can attack heavenly bamboo. Nandina mosaic, nandina stem pitting and cucumber mosaic have all been known to attack heavenly bamboo, although they are sometimes cultivar-specific. Nandina mosaic, for instance, commonly affects “Harbor Dwarf” and “Nana-purpurea,” while stem pitting usually affects “Nana-purpurea.” Cucumber mosaic and leaf spot, which cause light green or yellow spots in leaves, affect all species. None of these viruses have cures, so you will need to dig up and discard plants that contract them.
Heavenly bamboo is sometimes afflicted by bacterial leaf scorch, also called marginal leaf burn or simply leaf scorch. Leaves show symptoms when their margins turn brown, wither and die. Although the bacteria Xylella fastidiosa has been shown to cause leaf scorch, it can also result from insufficient watering, hot temperatures or other causes. There is no known cure, so if you identify leaf scorch, you can either leave the plant in the ground or dig it up and destroy it to prevent spread.
Heavenly bamboo can also be attacked by pests. Some examples include cottony cushion scale, which decreases vigor and causes white bumps to appear all over the host; mealybugs, which cause cottony tissue to form on leaves and stems; and whiteflies, which sap health by causing leaves to yellow and drop off. Cultural controls vary. In the case of cushion scale, for instance, install vedalia beetles and parasitic flies at the site. For mealybugs, pay attention to maintaining proper cultural conditions so that heavenly bamboo can withstand light predation. Whiteflies are eaten by lacewings, bigeyed bugs, and minute pirate bugs as well as ladybugs.