Why Are My Blueberry Bushes Turning Yellow?

Causes

• A variety of causes result in yellowing leaves on a blueberry bush, from water problems to high soil alkalinity or nutrient deficiencies. Determine the cause of yellowing leaves to ensure that the solution to the problem is effective and meets the needs of the blueberry bush; an improperly applied cure has the potential to be as damaging to a plant as the initial problem. Annual soil tests and tracking the amount of water the bush receives are key to keeping the blueberry bush healthy.

Water

• Too much water causes the leaves of the blueberry bush to swell, tear and turn yellow, and can lead to serious fungal problems, as fungi grow well in standing water and excessively damp soil. Make sure the soil around the blueberry bush drains water easily to prevent standing water problems. A lack of water causes the blueberry bush to become dehydrated and weak, which leads to sagging, yellow leaves that eventually curl in on themselves. Keep the soil around the bush moist.

High Alkalinity

• The pH of the soil is key to its health, and blueberry plants require a soil that measures on the acidic side of the pH range. The pH of soil is measured on a scale of 0 to 14, where numbers below 7 are acidic. High alkalinity, or a pH in the basic range, causes a condition called chlorosis, which turns the leaves of a blueberry bush yellow. Add acid fertilizer and decaying organic matter, like compost, to the soil around the bush; this will add acidity to the soil.

Nutrient Deficiency

• A lack of important nutrients causes the leaves of a blueberry bush to be weak and yellow. Zinc is a nutrient that factors into the color of the leaves, and a lack of zinc in the soil leads to yellow leaves, according to the Michigan State University Extension website. Add a fertilizer that contains zinc to the soil around the blueberry bush to increase the zinc content and restore the blueberry plant to health.