What Are the Causes of Yellow Leaves on Blueberry Plants?

Iron Chlorosis

• This type of chlorosis occurs when blueberry plants fail to obtain adequate amounts of iron from the soil. This is not necessarily caused by a lack of iron in the soil itself, but rather by the plant's inability to use that iron.

Solution

• Blueberry plants need acidic soil with a pH of 6 or less, preferably between 4.5 and 5.5, according to Oregon State University Extension. The more acidic the soil is, the more iron the plant obtains from the soil. Sulfur or iron chelate added to the soil lowers the pH. Work the material in to the soil for quicker results.

Other Types of Chlorosis

• Chlorosis occurs for many reasons, including moisture imbalance, root damage, or insect or disease problems, according to Missouri Botanical Garden. Treatment, such as insecticides, fungicides or proper irrigation, solves underlying problems and rectifies the issue of yellowing leaves, as well. Mulching to a depth of up to 5 inches also increase moisture retention and improves weed control, keeping plant stress to a minimum.