How toxic is heavenly bamboo (Nandina domestica), and why do its leaves not turn red

Heavenly bamboo (Nandina domestica) is an evergreen shrub whose leaves change from green to red under the different climates of the four seasons, and it is loved for this unique charm. However, some friends say that the heavenly bamboo they bought does not turn red in autumn and winter - why?

In fact, the color change of heavenly bamboo leaves is caused by many factors; the leaves may fail to turn red due to insufficient light, or because of temperature effects, care and management, and so on. In daily life, if you want to see heavenly bamboo leaves change from green to red in autumn and winter, then you have to move it out to an open balcony, let photosynthesis lower the leaf temperature, and then the leaves will turn yellow, orange or red, and later, after spring arrives and the temperature rises, the leaves will turn green again.

For four-season care of heavenly bamboo in terms of watering, in spring and autumn you can water about once every 7 days; in summer, when the weather is hot, you can water about once every 3 to 5 days; and in winter, watering about once every 10 days is fine. Remember not to add extra nutrient solution in winter.

So what should be noted when caring for heavenly bamboo? Is it toxic? The answer is yes: the whole plant of heavenly bamboo contains toxins, especially its red fruit. These toxins include cyanide and a variety of alkaloids, such as nandine, berberine and others, which may cause poisoning in humans, have a paralyzing effect on the nervous system, and may cause congestion and bleeding of the lungs, pleura and trachea, and in severe cases even endanger life. Therefore, contact with and consumption of any part of heavenly bamboo should be avoided.

In addition, because heavenly bamboo is an evergreen shrub, care requires extra vigilance against diseases, such as anthracnose, stem rot, leaf spot and other major diseases. Among them, anthracnose will produce round or irregular enlarged gray lesions on the leaves, and the edges of the lesions are sometimes black and sometimes dark brown; stem rot mainly causes the stem of heavenly bamboo to rot, so when you get close you will smell a sour, foul odor, and this disease mostly occurs under high temperature and high humidity in summer; the main feature of leaf spot is yellow or brown marks on the leaves and irregular markings along the leaf edges, brown in the early stage and turning gray-green later. Gardeners only need to promptly remove diseased leaves whenever they see the above diseases, and at the same time spray the diseased leaves with zineb or thiophanate-methyl for control.