Why Are My Blueberry Leaves Turning Red

Why Are My Blueberry Leaves Turning Red? How To Fix It

Blueberries are some of the tastiest fruits you will ever put in your mouth. This is the reason why they are popular in grocery stores. It is also the reason why many people use them to make various types of juices and smoothies.

Blueberries are easy to grow. Most of the time, their leaves look bright green as is the case with the leaves of most plants. However, they usually turn red. They do this because of several reasons.

In this post, you will learn why blueberry leaves turn red and what you can do about it.

What Is Causing Your Blueberry Leaves To Turn Red And How To Fix It?

Like the leaves of most plants, blueberry leaves are green in color. However, they only maintain this color during the growing season (spring and summer). In the fall season, the green leaves almost always turn red because of the cool weather. Therefore, if your blueberry leaves are turning red in fall, you have nothing to worry about. However, if they are turning red in any other season, there is a problem.

The problem could be a lack of magnesium, a lack of phosphorus, a bacterial disease, a fungal disease, a cultural problem, or cold exposure. Below you will find out more information about these problems and how to fix them.

1. Phosphorus Deficiency

When you notice your blueberry leaves are turning red especially in the spring season, you should know that your blueberries are most likely not getting enough phosphorus.

Blueberries prefer acidic soil. It is in soil with a pH of between 4.5 and 5.0 that they thrive. Therefore, if you grow them in soil with a pH of 5.5 or higher, they struggle. It is this struggling that makes them absorb fewer nutrients such as phosphorus resulting in phosphorus deficiency.

To know for sure if the soil where you’ve planted your blueberries has phosphorus deficiency, you should do a test.

If the test is positive, you should take action to increase your soil’s acidity. Because only this action will mitigate phosphorus deficiency symptoms. You can increase your soil’s acidity by adding organic matter such as peat moss, dried leaves, alfalfa, pine bark mulch, coffee grounds, and compost manure, to it.

2. Magnesium Deficiency

Magnesium deficiency also makes blueberry leaves to turn red. But unlike phosphorus, it does not make entire leaves to turn red. It only makes the veins to turn red.

Magnesium deficiency usually limits the production of chlorophyll resulting in the yellowing of leaves.

Therefore, when you notice leaf veins turning red and leaves turning yellow and dying, then you should know that you most likely have a magnesium deficiency issue in your hands.

If you believe you’ve got a magnesium deficiency issue in your handles, you should get Epsom salt and apply it around the base of each of your blueberry plants. This will increase the quantity of magnesium in the soil and fix the reddening of leaves.

3. General Nutrient Deficiency

As mentioned above, when the soil lacks certain nutrients, blueberry leaves become red. The deficiency of many more nutrients, in addition to magnesium and phosphorus, can cause leaves to turn purplish or red.

To fight general nutrient deficiency, you should have the soil in your ground tested. If you do so and find out it lacks sufficient quantities of several important nutrients, you should improve your soil using compost or manure.

Sometimes plants find it difficult to absorb nutrients because their roots are constantly waterlogged. So monitor the soil around the root balls of your blueberries. If the soil is ever waterlogged, change your watering practices, or improve the soil using pine bark.

4. Fungal Diseases

Blueberries are affected by bacteria, viruses, and fungi. If you are growing blueberries commercially, you should be very concerned about these three causes of disease because they can render your harvest useless and make you incur a heavy financial loss.

Several diseases caused by bacteria, fungi, and viruses cause blueberry leaves to turn red. The two most common ones caused by fungi are phomopsis twig blight and powdery mildew.

Phomopsis twig blight often starts as a necrotic brownish lesion on the twig. This is followed by spots developing on twigs and infected stems wilting during the summer season. The disease is, however, characterized by leaves turning from green to brown or red.

The fruits can also rot at harvest. The solution to this fungal disease is to prune and burn the twigs that are infected. And to apply lime sulfur to breaking leaf buds.

Powdery mildew is a fungal disease that attacks many plants. It is characterized by the growth of a powdery white substance on leaf surfaces. With time, as the disease progresses, the leaves become chlorotic (yellowish) and will develop red borders before starting to drop from affected plants. The best way to address this fungal disease is to apply a good fungicide to stop and then prevent the disease.

5. Bacterial Diseases

There are several bacterial diseases that can make blueberry leaves to turn from fresh green to red. The most common one is called blueberry leaf scorch. This disease is caused by a bacteria called Xylella fastidiosa. When a plant is attacked by this bacteria, the flow of nutrients and water becomes restricted resulting in stunted growth, reduced productivity, and death. Since this disease restricts the flow of nutrients, it also causes green leaves to become reddish.

If you believe parts of your blueberry bush or bushes have been affected by this disease, you should remove them and destroy them. If the disease is common in your region, you should properly use products such as thiamethoxam on your bushes to prevent the disease from attacking your plants.

6. Cold Exposure

As mentioned earlier, blueberry leaves almost always turn red in the cool season because of the cold weather. This discoloration is natural and you should not worry about it. It naturally fades when the weather becomes warmer.

However, it can persist beyond cold weather if it is caused by something else other than the cold. If it persists, investigate, and take corrective action before it is too late.


Blueberry leaves turn red in fall due to the cold weather. So if your blueberry leaves are turning red after the summer season, you’ve got nothing to worry about. However, if they are turning red in any other season, you should be worried. The things that can turn your blueberry leaves in any other season other than fall include mineral deficiencies, diseases, and cold weather. The good news is that you now know about these things and how to fix them.