Peppers are top of my list of plants to grow each year, and I’m sure they’re on your list, too. Growing peppers is relatively easy, but that doesn’t mean things can’t ever go wrong.

An issue like yellowing leaves can mean your plant is a bit under the weather, or it could signal a much more serious problem.

It can be disheartening to see your plants struggle, but understanding the reasons behind this discoloration can help you take the right steps to restore your plants back to good health.

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6 POTENTIAL CAUSES FOR YOUR PEPPER PLANT LEAVES TURNING YELLOW

 

Here are the common culprits behind yellow pepper leaves:

  • Inconsistent watering
  • Nitrogen deficiency
  • Nutrient deficiency
  • Disease
  • Pests
  • Cold weather

Now, let’s look at each of these in more detail so you can get to the bottom of your pepper plant problem.

yellowing pepper leaves from not enough water inside an apartment

1. INCONSISTENT WATERING

 

Ever wonder why your pepper plant leaves start turning yellow, even though you’re watering them regularly? Well, inconsistent watering might just be the culprit. In fact, it’s one of the most common reasons why pepper plants get stressed out and start showing those telltale yellow leaves.

Signs of Water Stress:

Pepper plants are pretty picky when it comes to water. If they’re not getting enough, they’ll let you know by turning those leaves yellow. But here’s the kicker: giving them too much water can be just as bad. You might feel like you’re gardening between a rock and a hard place, but it’s the pepper plant’s only way of saying, “Hey, something’s not right here!”

Solution

Consistency is key, especially during drier weather conditions. Try to water your pepper plants regularly, but let the soil dry out slightly between waterings to prevent waterlogged roots and water stress.

The best way to water is slowly and deeply. The goal is to have moist soil at the root level that’s the wetness level of a wrung-out sponge. Watering methods like drip irrigation and ollas, like the ones from GrowOya, easily provide this type of watering.

If you are watering by hand with a hose or watering can, water slowly, and always water the base of the plant, not the leaves.

And if you’re not sure when to water, stick your finger into the soil—if it feels dry an inch or so down, it’s time to give your pepper plants a drink.

2. NITROGEN DEFICIENCY IN PEPPER PLANTS


Another potential cause of yellow leaves could be nitrogen deficiency. Nitrogen is like fuel for plants—it’s essential for leaf growth and development.

Signs of Nitrogen Deficiency:

If your pepper plants aren’t getting enough nitrogen from the soil, the older leaves will likely be the first to turn yellow. The new growth might still look green and healthy. You might also notice some brown spots on the yellowed leaves.

Solution:

If you think a lack of nitrogen is your culprit, then it’s time to give those plants a nitrogen boost. Go for a balanced, slow-release organic fertilizer that’s got plenty of nitrogen in it, such as MicroLife’s Ultimate or Fox Farms Happy Frog.

You can also try things like compost or aged manure to beef up the nitrogen levels in your soil. Either way, your pepper plants will thank you by putting on some serious growth and getting back their vibrant green color.

Quick warning: I recommend a balanced fertilizer because you don’t want to add too much nitrogen. That might encourage your plants to focus only on forming new leaves, instead of flowers and fruits (yes, peppers are fruits!).

3. NUTRIENT DEFICIENCIES IN PEPPER PLANTS

In addition to nitrogen, peppers need a number of essential nutrients to grow big and strong. Plants—they’re just like us! Yellowing leaves can be a sign of just a general lack of nutrients, including calcium, magnesium, sulfur, and iron.

Signs of Calcium Deficiency:

Calcium is crucial for strong cell walls and healthy growth. When your plants don’t get enough, their leaves might start to curl and turn a yellow-green. You might also notice brown spots on your fruits. This is called blossom end rot, and it’s caused by the plant not being able to absorb calcium properly.

Solution:

Calcium deficiency can be overcome by giving your plants the right balance of nutrients. Adding soil amendments like gypsum or lime can give them a quick boost. You can also use fertilizers that have calcium, like calcium nitrate.

Make sure your soil isn’t too acidic because that can mess with how well your plants are able to take up calcium. Spraying a bit of calcium on the leaves can also do the trick. (Remove bruised fruits and water more consistently if your peppers are suffering from blossom end rot.)

yellow pepper growing on a pepper plant. The yellow pepper is showing signs of blossom end rot.

Signs of Magnesium Deficiency:

Another essential nutrient your pepper plants crave is magnesium, which plays a role in chlorophyll production. Chlorophyll is what gives leaves their pretty green color, so a lack of magnesium can lead to leaves fading to yellow. Leaves might look striped or kind of patchy.

Solution:

When your pepper plants aren’t receiving adequate magnesium, give them a hand by sprinkling some Epsom salt around their base or mixing it into their water. Mixing in compost with your soil can also help. Fox Farms Bush Doctor Cal-Mag Plant Supplement is an organic fertilizer that can actually be used to add both calcium and magnesium.

One last thing: try not to overdo it with potassium fertilizers because they can mess with how your plants soak up magnesium.

Signs of Sulfur or Iron Deficiency:

Sulfur and iron are both important for overall plant health. When pepper plants don’t get enough sulfur, their leaves can start to yellow from the middle, signaling trouble. Iron-deficient plants tend to produce yellowed, stunted leaves.

Solution:

To tackle these deficiencies, I recommend adding fresh compost or soil conditioner to the surface of your soil or fertilizing with an all purpose organic fertilizer as mentioned above.

4. DISEASE AND VIRUSES IN PEPPER PLANTS

Unfortunately, a number of different bacterial, fungal, and viral infections can cause yellow leaves on your beloved pepper plants. The earlier you spot the signs of illness, the better your plants’ chances of being nursed back to health.

Bacterial Leaf Spot:

This bacteria causes a bunch of little brown spots surrounded by yellow to appear on your leaves.

Solution:

There’s not really an effective solution except to remove the affected plants and avoid planting peppers in the same spot for a couple of seasons. You can prevent it, though. The bacteria love warm, humid conditions, so keep things dry and tidy in your garden (again, don’t water the leaves of your plants).

Fungal Disease:

Fungal diseases can also turn your pepper plant leaves yellow. They start as small yellow or brown spots that might have a darker ring around them. If left unchecked, these spots can spread and lead to some serious wilting and weakening of your plants.

Solution:

Make sure your plants have enough space to breathe by pruning regularly, and avoid watering the leaves of your plants to prevent fungal diseases. You can also spray a fungicide like Captain Jack’s Copper Fungicide to stop the spread.

Mosaic Virus:

This sneaky virus can cause all sorts of trouble for your pepper plants. If your leaves start showing mottled patterns or weird distortions and then turn yellow, mosaic virus might be to blame.

Solution:

Unfortunately, once a plant catches it, there’s no cure. You’ll need to remove affected plants and all plant debris ASAP. To prevent the spread of the virus, make sure to clean your pruners with some rubbing alcohol after each use, and keep your garden free of weeds.

Phytophthora Blight:

Phytophthora blight is another nasty one caused by a fungus. Leaves might appear yellow for a bit before they wilt and the entire plant collapses.

Solution:

Water gently to avoid splashing soil (which could potentially be infected) up onto your plants as a general rule. Good drainage is also critical to prevention, which is one of the reasons we recommend gardening in raised beds. Remove affected plants to prevent the spread of disease. Treat the area with something like Captain Jack’s Copper Fungicide.

pepper leaf with bacterial leaf spot virus

5. PEPPER PLANT PESTS

I hate to break it to you, but pests can also cause yellowing leaves. (Why are there so many things coming after our plants?!) The good news is that healthy pepper plants can often fend for themselves against pests. It’s really only when your plants are stressed out that they invite serious pest issues.

Signs of Pest Infestations:

Among the most common trouble-makers for peppers are flea beetles and aphids. Flea beetles are these tiny jumpers that can chew up your leaves faster than you can say “pest control.” Aphids are sneaky sap-suckers that cause your leaves to turn yellow and curl inward.

Solution: 

We’ve got a few tricks up our sleeve to deal with harmful pests. I recommend organic treatments like Neem oil or insecticidal soap to keep pests in check without causing harm to the good bugs or the environment. And if you’re really serious about protecting your plants, consider investing in an Arber Outdoor Kit—it’s like a fortress for your garden, keeping pests out while your plants thrive.

Check out this post for more tips on how to handle an aphid infestation.

Another organic way to deal with pests is to welcome good insects into your garden. Plant lots of flowers to roll out the welcome mat for ladybugs and lacewings that like to eat tiny critters like aphids. They’ll gladly pitch in to keep your garden pest-free (they’ll even help pollinate your fruiting plants).

aphids on the back of a pepper plant leaf

6. COLD WEATHER

Pepper plants thrive in warm weather and can experience stress when temperatures drop, especially during unexpected cold spells. They really can’t tolerate frost at all, which means temps below 33°F can harm or even kill your plants. Leaves might turn yellow or even black and look wilted after a freeze.

Solution:

If you’re expecting cold weather, protect your plants with row cover or frost cloth. Even better, dig up the root ball of your pepper plants and transfer them to pots so that you can bring them indoors during cold nights. Peppers are perennial, so you can actually plant them back out in your garden come spring.

I hope this guide helps you identify the problem with your pepper plants and put them back on the road to recovery. With any luck, you’ll still get a bounty of delicious peppers this summer!