Blueberry Leaves Turning Red: 5 Fixes For the Problem

Wondering, Why are blueberry leaves turning red? This could be due to several reasons, like a change in season, nutrient deficiency, or even water stress. But don’t worry! I’m here to help you understand why it’s happening and what you can do to fix it.

Stick around, and you’ll get all the tips to keep your blueberry plants happy and healthy.

What Causes Blueberry Leaves Turning Red?

Blueberry leaves turning red can be caused by environmental stress, nutrient deficiencies, or seasonal changes. Cold temperatures and diseases such as blueberry leaf rust can also be the reason behind this color change.

Autumn Season

One of the first things I always check when I see my blueberry leaves turning red is the season. During the fall, it’s totally natural for blueberry leaves to turn red as part of their preparation for winter. 

Just like how trees change colors in autumn, blueberries also get those red shades. When the temperatures start to drop, the plant is getting ready to go to sleep (dormancy).

Why does this happen?

When the weather cools, chlorophyll breaks down, and the red pigments, called anthocyanins, come through. I remember once in late September, I saw my blueberry leaves turning red, and I panicked, but then I realized it was just fall!

You don’t need to do anything if it’s fall. This is completely normal. I usually just let my plants do their thing, and by spring, they are back to producing leaves and berries.

Lack of Nutrients, Especially Nitrogen

Now, let me tell you about another time I noticed red leaves way before fall. This could be a sign that the plant isn’t getting enough nutrients. Blueberries need a lot of nitrogen to grow healthy leaves.

Without enough nitrogen, the leaves can turn red or purple because the plant can’t produce enough chlorophyll.

You’ll notice that the leaves at the bottom of the plant will start turning red first. When I first saw this, it was confusing because it wasn’t fall. That’s when I realized my plant needed a bit of a food boost!

Soil Is Too Alkaline

One thing I learned the hard way is that blueberries are really picky about their soil. They love acidic soil. If the soil isn’t acidic enough, they can’t take in all the nutrients they need, and one sign of this is the leaves turning red.

Acidic soil has a pH of around 4.5 to 5.5. If the pH gets too high (more alkaline), your blueberry plants will struggle.

I’ve found that a good way to check this is with a simple pH testing kit you can grab at a gardening store. 

When I checked my soil, I saw that the pH was way too high, and that was why my leaves were turning red.

Water Stress: Too Much or Too Little?

Water is something we often overlook, but blueberries are super sensitive to how much they get.  In the Scientia Horticulturae Volume 316, it is clearly written that both overwatering and underwatering can harm plants.

Both can stress the plant, causing the leaves to change colors.

When I was a beginner, I overwatered my blueberries, thinking more water would make them grow faster. Instead, the leaves turned reddish, and the plant looked sad.

A study shows that when you overwater, plants can’t take up water efficiently, despite wet soil. As a result, blueberries can get water stressed.

So, what does water stress look like? The leaves may start turning red, but also look out for wilting or dry edges. In my case, when I underwatered, the plant leaves became dry and red.

But, when I overwatered, the leaves turned red but looked a bit swollen.

Fungal Diseases

Another thing I noticed in one of my plants was red leaves that didn’t seem to match any of the other causes. Turns out, it was a fungal infection. Fungal diseases like leaf spot can cause red or purple spots on the leaves, and it can spread if not treated.

Fungi are a leading cause of root and leaf diseases, particularly in soggy environments, researchers report. A study explains that overwatering creates the perfect environment for fungi to attack.

Fungal spots can look like tiny red or purple blotches that appear out of nowhere. I remember thinking my plant was just stressed, but as more spots appeared, I realized it was something more serious.

If you see fungal spots, remove the affected leaves and dispose of them (don’t compost them). Let’s now look at how you can treat red blueberry leaves.

How to Fix Blueberry Leaves Turning Red? 5 Things To Do

Now that we know what causes blueberry leaves to turn red, let’s talk about what you can do to fix it. Trust me, I’ve been there, and once you figure out the issue, it’s not that hard to get your plants back on track.

1. Check the Season and Don’t Worry

If it’s fall, just relax. Blueberry plants naturally change colors in autumn, so you don’t need to stress about red leaves during this time. I’ve learned to enjoy the red colors because it means my plants are healthy and getting ready for winter.

You don’t have to fix this because it’s not a problem!

2. Add Fertilizer for Nutrient Deficiency

According to Advanced Research and Review in Agronomy, fertilizers are crucial for promoting healthy roots, leaves, and flowers. How? By ensuring nutrient balance.

So, if you’ve noticed red leaves outside of the fall season, check for nutrient deficiencies. In my case, nitrogen was the issue, and once I added a nitrogen-rich fertilizer, the plants bounced back quickly.

What Kind of Fertilizer Should You Use? Go for a fertilizer that’s made for acid-loving plants. These fertilizers have the right nutrients, especially nitrogen. I used one specifically designed for blueberries, and it made a world of difference.

You can also use organic or bio fertilizers for blueberry plants. Nature reports that bio-organic fertilizers can restore soil fertility. So, they are a great alternative to chemical or commercial fertilizers.

That’s not it.

According to the Encyclopedia of Sustainable Technologies, organic fertilizers are made from natural sources like plant material and compost. This means they are eco-friendly (and not harmful to you).

How Often Should You Fertilize? In my experience, you don’t want to overdo it. I usually fertilize my blueberries in early spring and sometimes again in late spring if needed. Too much fertilizer can cause problems, so keep it balanced.

3. Adjust the Soil pH

If the soil pH isn’t right, your blueberries won’t be happy. I always keep an eye on my soil’s pH, and if I notice red leaves, it’s one of the first things I check. Acidic soil is key to keeping blueberry plants healthy.

How to Lower the Soil pH? If you discover your soil is too alkaline, you can lower the pH by adding sulfur or using peat moss. I’ve used both, and they work really well. Just mix them into the soil around the plant, and you should see improvements.

I test my soil every spring before I start fertilizing, just to make sure everything is still balanced. If you keep the pH in the right range, you’ll avoid a lot of problems.

4. Fix Your Watering Routine

Watering is something I’ve had to experiment with over the years, but I finally found what works best. Blueberries like consistent moisture, but they don’t want to be drowned.

How Often Should You Water? I water my blueberries deeply about once or twice a week, depending on the weather. If it’s really hot, I water more. But, I always let the soil dry out a bit between waterings so the roots don’t get waterlogged.

How Can Mulch Help? Mulch is my secret weapon for keeping the soil moist without overwatering. It helps retain moisture but also allows the soil to breathe. I use pine bark or wood chips, which also help keep the soil acidic.

5. Treat Fungal Infections

If you think your blueberry plants might have a fungal infection, like I did once, you need to act quickly. Fungal infections can spread, and they won’t go away on their own.

An easy way to treat fungal infections is to trim affected parts and repot the plant in fresh soil, according to a report. Moreover, Proper watering is one of the best ways to keep plants healthy and disease-free, says Microbiological Research Volume 242.

I also use an organic fungicide because it’s safe for my plants and the environment. You can spray it on the affected leaves, and it usually clears up the infection after a few treatments.

Keeping your plants spaced out and making sure they get good air circulation can also prevent fungal diseases.

Final Words

If you notice blueberry leaves turning red, here’s what you should check:

• Look at the season – it might just be fall!
• Test your soil pH and adjust if needed.
• Check for nutrient deficiencies, especially nitrogen.
• Make sure you’re watering the plant properly.
• Watch out for fungal infections and treat them quickly.

That’s all.