Yellow Leaves on Blueberry Bushes

Nutrient Imbalance

• If your plant is not getting enough nitrogen, the leaves will begin to yellow and may appear spotted. Iron deficiency will also cause your blueberry leaves to yellow, this is usually related to poor pH of the soil. Too many nutrients can cause as much problem as not enough. Too much magnesium will also cause the leaves to yellow. This can occur when the pH is incorrect for blueberries or your plant is not receiving enough moisture. It's important to follow the nutritional guides for your variety of blueberry plant.

pH

• Blueberry plants thrive at a pH of about 4.2 to 5.2. If the pH of the soil is too high, or alkaline, the plant is unable to use the iron in the soil. It is recommended that you test your soil if you suspect a pH problem. Over correcting the pH can lead to an equally sick blueberry plant. To correct pH, add pine needle mulch and to correct an iron deficiency caused by incorrect pH, apply iron chelate to the soil or to the leaves.

Sunlight

• Blueberries need between 6 to 8 hours of sunlight a day. If your blueberry plant is receiving insufficient sunlight, the leaves may turn yellow and your plant will weaken and become susceptible to disease. If your blueberry plant is not receiving at least 6 hours of sun a day, consider moving it to a location where it can get additional sunlight.

Insufficient Drainage

• When water isn't allowed to flow through the soil but collects among the roots, it can not only rot your blueberry bush's roots, it can suffocate them, preventing nutrients to reach the plant. One of the first signs of this is yellowing leaves that may fall from the plant. If your blueberry is planted in a container, make sure there are adequate drainage holes. For blueberries planted in the ground, amend the soil heavily with compost and never leave your blueberry in standing water.

Disease and Insect Attack

• Many insects and diseases can cause blueberry leaves to yellow. Aphids feed on the sap of the leaves, draining their nutrients, causing them to discolor. Fungi such as leaf rust cause rust-colored spots to appear on your leaves before they turn yellow and fall from the plant. If your leaves have a mottled yellow and green appearance, it could be Blueberry Mosaic Virus. Spray your blueberry with an insecticide and/or fungicide to eliminate fungal and insect infestation. For virus infection, allow the disease to run its course, separating it from other plants. If necessary, destroy the infected plant.