What Causes a Bamboo Plant to Turn Yellow?
A bamboo plant's leaves will turn yellow and fall off the plant as a normal part of the growth process. This process will happen throughout the year, but it is most noticeable in the spring when new growth is triggered by the warming sun after the dormant winter. As bamboo grows new leaves, the plant recycles its old leaves: They yellow and fall off. Let the fallen leaves work as a natural mulch that supplies the bamboo plant with silica, which helps future growth. A healthy bamboo plant will have a mix of green, yellow and unfurling leaves.
If you see yellow stripes in the center of the bamboo plant's leaves, it may be infested with mites. Bamboo mites feed on bamboo leaves, and the yellowish streak in the leaf is the result of them sucking out the leaf's juices. They live on the underside of the leaves and can be seen (along with their webbing) with the help of a magnifying glass. Mites do not cause excessive damage. They can be controlled by quarantining new plants and by treating infected plants with an insecticidal soap.
Food and Water
Bamboo--like many plants--will have its leaves turn yellow if the plants are getting the wrong amount of nutrients or water. The most common cause of houseplant death is over-watering--and the first symptom is yellowing leaves. Even though bamboo likes a lot of water, the plant does not like to have saturated roots or to be left in standing water. If your bamboo plant's leaves begin to yellow and curl during a dry season, water it. Feeding your bamboo plant with compost is enough to keep it happy, but if you use a fertilizer, make sure it is a grass fertilizer. Bamboo is a type of grass, and a fertilizer designed to kill weeds and grass will cause your bamboo to turn yellow and die.