Skip to Content

Are Your Blueberry Leaves Turning Red? (7 Possible Causes)

Are Your Blueberry Leaves Turning Red? (7 Possible Causes)

Share this post:

Disclaimer: Some links found on this page might be affiliate links. If you click an affiliate link and make a purchase, I might earn a commission. As an Amazon Associate I earn from qualifying purchases.

Around a year ago, while I was tending to my blueberry bushes, I noticed that some of their leaves appeared red instead of their usual verdant green. 

At first, I didn’t think much of it. Blueberry leaves change colors all the time, especially at the start of the season. But when the color shift persisted, I started to get worried. 

I’ve heard horror stories of fellow blueberry enthusiasts losing all their plants because of some mysterious infection, and I feared that my plants might have been affected by the same thing. 

After hours of research, I was thankfully able to identify and fix the issue. I’m here to share my knowledge and help others who might be facing similar concerns with their blueberry leaves.

In a nutshell, here are the potential reasons why your blueberry leaves are turning red:

  1. Interveinal red blueberry leaves
  2. Phosphorous deficiency
  3. Red-spotted leaves
  4. Cold exposure
  5. Viral and fungal infections in blueberry plants
  6. General nutrient deficiency in blueberry plants
  7. Wrong soil pH level for blueberry plants

Some of these reasons can be serious, potentially requiring the removal of the affected blueberry plant to safeguard others. 

Continue reading to discover solutions for some of these issues and identify those that may be more challenging to fix.

Why Would Blueberry Leaves Turn Red?

Let us go over the leading causes of blueberry leaves turning red so you can determine when you should be worried about your plant’s health.

1. Interveinal Red Blueberry Leaves

Blueberry Plant Leaves With Red Veins

If you look at your blueberry plant and the veins on the plant’s leaves are turning red, this can indicate that the blueberry plant has a magnesium deficiency.

Suppose your blueberry bushes aren’t getting enough magnesium, either due to a lack of the mineral in the soil or the blueberry bush being unable to absorb it. In that case, the blueberry plant will reduce its chlorophyll production.

The chlorophyll in the blueberry’s leaves is what gives the leaves their lovely green color. The veins of the blueberry plant’s leaves will start to turn yellow first before fading into a red color.

Magnesium deficiencies can lead to diseases that are incurable and can easily spread to other blueberry bushes. Hence, you need to treat it as soon as you can.

2. Phosphorus Deficiency in Your Blueberry Plant

If your blueberry leaves are between a maroon and red color in spring, this could indicate a Phosphorus deficiency in your blueberry plant.

Blueberries generally require a high acidity level in their soil to thrive and produce good-quality blueberries of a larger quantity (3.8 to 5.5).

However, the pH level needs to be watched closely and maintained well throughout the plant’s growth cycle. An imbalance in pH levels can hinder the blueberry plant’s ability to take in enough Phosphorus. 

If the pH level is excessively high, the blueberry plant will struggle to absorb an adequate amount of Phosphorus, while too low a pH inhibits the plant’s ability to take up the essential Phosphorus required to grow healthy.

Both of these scenarios can cause the plant to have a Phosphorus deficiency. This deficiency can weaken the blueberry plant and leave it susceptible to illnesses such as blossom end rot and poor fruit development.

3. Red Spotted Leaves

If the blueberry’s leaves aren’t completely red but have red spots all over them, the blueberry plant may have been affected by a virus called the Red Ringspot Disease (RRD). This is the virus I was talking about at the beginning of the article—the one every blueberry farmer fears!

Red Ringspot manifests as red spots on the blueberry plant’s leaves. These red spots are most visible in the summer when the leaves turn a pale green, as this will make the red stand out.

Regrettably, RRD is an incurable disease. It’s fast-spreading and aggressive, capable of infecting an entire field of blueberry plants in a matter of days. The only good news is that it’s a relatively rare disease, affecting only around 5% to 10% of blueberry plants in the US. 

Blueberry plants with RRD bear a life-long impact, and cuttings taken from the infected plant will also carry the disease. 

Since scientists have yet to understand the cause of the disease, the only available measure is to isolate or remove infected bushes. 

While safe to eat, fruits harvested from RRD-infected plants look and taste unappetizing since they often exhibit premature ripening, discoloration, and shrinkage. 

This is why RRD is a commercial farmer’s worst nightmare; no one would want to buy diseased-looking fruits, no matter how cheap!

4. Cold Exposure

Blueberry Plant With Frost

Blueberries are cold-weather hardy plants, and they tend to grow comfortably in plant hardiness zones two through eight. 

But if it gets unusually cold, the blueberry leaves may turn red or purple. This can create issues for your blueberry plant if it remains in these cold temperatures or if the temperature drops further. It might result in your blueberry bush losing its leaves and potentially dying.

To catch early signs, regularly check the plant during chilly weather. If you notice discoloration or stress, cover the blueberry bush with a cloth or blanket during cold nights. 

You can also apply a layer of mulch around the base to help insulate the roots and protect the plant from extreme temperature drops. 

5. Viral and Fungal Infections in Blueberry Plants

Blueberry bushes are prone to a wide variety of diseases caused by viruses, bacteria, and fungi that grow on the plant. 

These infections are generally only a huge cause for concern with commercial blueberry growers as they have many plants that are at risk of getting infected by these illnesses.

But these can be a concern for home blueberry growers, too, as these diseases can affect the fruit production of the plant or even the fruit itself. 

Several diseases can cause the leaves of the blueberry bush to become red-mottled or blotchy. Some of these may even cause the leaves to split and look burned at the margins of the leaves. 

One of the most common afflictions that blueberries can get is Phomopsis twig blight, caused by a fungus that first infects the lower branches of the bush before spreading upwards.

Then there’s also blueberry leaf scorch, a viral infection that can cause the areas around the veins of the leaves to turn red. These can be transmitted from plant to plant, and they can easily be misdiagnosed, making them challenging to control.

6. General Nutrient Deficiency in Blueberry Plants

Wild Blueberry Plant With Red Leaves

When the soil of your blueberries lacks certain nutrients, the plant’s leaves can begin to turn red. This isn’t limited to just phosphorus or magnesium deficiencies but can also result from a general lack of nutrients in the soil.

If not for nutrient deficiencies in the soil, there might be an issue with the blueberry plant’s ability to absorb the available nutrients from the soil.

One of the main causes for this general nutrient deficiency is a lack of good fertilization practices or waterlogged soil, hindering the plant’s ability to take in all the nutrients it needs to thrive in your garden.

7. Wrong Soil PH Level for Blueberry Plants

As previously mentioned, if the soil that your blueberry plant is planted in does not have the right pH level, then this can cause a problem for your blueberry plant. Blueberries require acidic soil to thrive.

The soil’s acidity needs to be between 4.5 and 5.0. If the pH level goes lower or higher than this, the plant can begin to suffer in various ways. Not only will the plant struggle to absorb Phosphorus from the soil, but it’ll also affect the absorption of all other essential nutrients.

The result is a general nutrient deficiency that can weaken the blueberry plant, leaving it open and susceptible to various diseases and infections. Most of these diseases can turn the leaves of your blueberry plant red.

How to Fix Red Blueberry Leaves

Now that we know what may have caused the leaves of your blueberry plant to turn red, we can now go over the possible ways you can fix these problems and get your plant back to prime health. 

Close Up Of Blueberry Plant With Leaves Turning Red

Disease Treatment Options

Before you begin any disease treatment for your blueberry plants that you think may be infected with a virus, fungus, or disease, you should first take a sample of the blueberry bush with leaves attached and place it into a zip-lock bag.

Take the blueberry sample to a local university extension office and ask them to diagnose the problem. This service is often available at little to no cost, making it a cost-effective way to gain expert insights into what is ailing your plant.

Many viruses and fungi cause the same symptoms to appear in your plant, so it’s essential to know which one you’re dealing with. 

Some diseases, like Phomopsis blight, can be treated with a diluted lime-sulfur sprayed on newly forming leaves. 

But others, particularly those caused by viruses, aren’t treatable. Blueberry scorch is a prime example of such an untreatable disease.

Increase The Soils PH Level

Coffee Grounds

To help your blueberry plant absorb enough Phosphorus and other essential nutrients, ensure the soil’s pH level is within the blueberry plant’s preferred range. 

You can conduct a soil test to determine the soil’s pH level. Soil testing kits are readily available at garden centers, online retailers like Amazon, and through local agricultural extension offices.

If the pH level is low, add some coffee grounds, dried leaves, peat moss, pine bark mulch, or composted manure to your blueberry soil. These additions will help raise the pH level to the right level and keep your blueberry plants happy.

Increase Magnesium in the Soil

If your blueberry plant leaves are turning red due to a magnesium deficiency, then you can try to increase the magnesium in the plant’s soil. 

A great way to add some magnesium into the soil quickly is to use Epsom salt.

Epsom salt is a lovely naturally occurring compound that contains sulfur, magnesium, and oxygen. These compounds are needed for healthy plant growth, especially the magnesium that helps the plant produce its chlorophyll.

Keep in mind a magnesium deficiency can also affect the way the blueberry plant absorbs other nutrients, which can negatively affect the plant’s growth and the fruit. So, just buy some Epsom salt and mix it into the first layer of topsoil around your plant.

Remove the Blueberry Plant

There are some instances where the blueberry plant isn’t viable and cannot be saved due to an incurable infectious disease.

When this is the case, you will need to remove the plant and destroy it before the infection spreads and contaminates all of your blueberry plants.

This is a worst-case scenario and should not be the first conclusion that you jump to until you get confirmation from a professional. 

Remember that several conditions will present the same symptoms, and this scenario is only the conclusion for one of them.

Fertilize Blueberry Plants Correctly

Adding Fertilizer To Blueberry Bush

To avoid red leaves on your blueberry plant, ensure it has the right amount of nutrition so it won’t suffer from nutrient deficiency.

Fertilization is an essential aspect of keeping your blueberry plants in pots, as they’ll only receive nutrients from what you add to their soil. You need to ensure you give your blueberry plant a well-balanced fertilizer at least once a month during its growing season.

Fix Waterlogged Soil

If your blueberry plant’s soil is waterlogged, the plant will have difficulty absorbing the nutrients it needs to survive. This can lead to a nutrient deficiency that will cause the plant’s leaves to turn red.

To help the plant get back to normal, you need to either repot your blueberry plant or fix the soil while the plant is still in it; whichever way you find most manageable. 

If you decide to replant the plant, replace the old soil with well-draining soil containing peat moss. This not only aids in proper drainage but also contributes to maintaining the soil’s pH level.

To improve the plant’s potted soil, carefully mix in some peat moss or perlite. Be cautious not to disturb the plant’s roots, but get close enough to facilitate proper drainage and prevent waterlogging.

Keep the Blueberry Plant Warm

Protecting Blueberry Bushes From Cold Weather With Covers

One of the reasons why a blueberry plant’s leaves will turn red is that the plant is exposed to extremely cold temperatures. The blueberry plant is hardy, but it cannot handle extreme temperatures in either direction.

So, to help your plant recover from the cold and to prevent the color change in the leaves from happening again, you need to keep the plant at a constantly warm temperature. 

If you’re comfortable in the temperature without a jacket, then this should be perfectly fine for the blueberry plant. If not, cover the plant with a protective layer.


Is it normal for blueberry leaves to turn red in the fall?

Yes, blueberry leaves develop a maroon color during fall as a response to lowering temperatures. The plant’s leaves should go back to their normal green color as the temperature increases, typically during spring. 

How do you identify blueberry leaf disease?

To identify the disease your plant is afflicted with, examine its foliage. Look for tell-tale signs of infections and illness, such as discoloration, changes in leaf texture, spots, or lesions. 

Take note of these irregularities and seek guidance from local horticulturists or extension services. 

If you don’t have access to these services, use online resources and plant care guides like this one (and many others on my page!) to help you compare the symptoms with known diseases.

Can pests change the color of blueberry leaves? 

Yes, pests can contribute to changes in the color of blueberry leaves. 

Spider mites and aphids, for example, feed on the plant’s sap, leading to the yellowing of the leaves. Other pests, like scale insects, may transmit diseases that affect the foliage, further altering its color. 

Make sure to regularly monitor your crops for pests to preserve their health and vibrancy. 

Final Thoughts

When the leaves of your blueberry plant turn red, it’s not always a cause for concern. However, in some instances, it could indicate the development of an incurable disease. Rather than panicking, look for the cause as it may be easily fixable. Good luck with your blueberry plant!

Share this post: