If your bamboo's leaves are turning yellow, check the calendar. If it's spring, some yellowing and leaf drop is normal as new leaves come in. If yellowing occurs at the height of the growing season, that's quite another story. According to the University of Georgia, bamboo is a hardy perennial grass that has few pests or problems. Give it plenty of light, proper moisture, warmth and the right soil to correct the problem of yellowing leaves.
Low Soil pH
Check the pH of the soil near the roots of a yellowing bamboo. If the pH of the soil is too alkaline, the leaves will begin to turn yellow between the leaf veins. Bamboo prefers a pH range that is slightly acidic, between 5.0 and 7.5. Amend the soil with sulphur to raise the pH above 5.0, following the directions on the packaging for correct proportions and frequency of application.
Poor Soil Drainage
Check the soil drainage near the culms, or roots of the bamboo. If the bamboo is potted, make sure the drainage holes in the bottom of the pot are open and draining freely. Bamboo roots will rot if they stand in waterlogged soil, and one of the first symptoms is yellowing and dropping leaves. Amend poorly draining soil with equal parts peat and sand for a loose, well-drained mix. Repot container bamboo in fresh soil, with a inch of gravel on the bottom to aid drainage. Allow soil to dry out between waterings to help correct yellowing.
All plants need water to move nutrients through their roots and stems to the leaves. Bamboo can be drought-tolerant, but cannot withstand dehydration for long periods. Leaves will yellow and drop as the plant tries to conserve water in its stems and roots. Irrigate outdoor bamboo to a depth of 5 inches every few weeks during the growing season to keep it healthy. Water indoor bamboo every two weeks.
Bamboo naturally stretches toward the light, and grows best in bright sun with some dappled shade. Young plants are more shade tolerant than mature bamboo. Adequate light is needed for bamboo leaves to produce food through photosynthesis in its leaves. Insufficient light leads to less chlorophyll in the leaves, causing them to yellow and drop off. Move an indoor bamboo to a brighter area near a window if this is happening. Outdoors, cut back surrounding vegetation to let in more light.