Potato Plants Turning Yellow: 8 Common Causes (Explained)

Are you a lover of potato farming but have recently noticed a worrying trend in your garden? Have your previously flourishing potato plants begun to display yellow leaves? If so, then you’ve stumbled upon the right article. We’re here to get to the root of this issue, so you can have healthy, green potato plants once again. 

We’ll answer your big question: Why are your potato plants turning yellow? We’ll explore all the common causes of this disheartening phenomenon, providing you with a detailed explanation for each. We’ll also give you the knowledge to avoid this in the future. Let’s turn that frown upside down and those potato leaves back to green!

7 Reasons Why Your Potato Plants Are Turning Yellow?

Many factors cause potato plants to yellow. From nutrient deficiencies to disease, water stress to pests, each cause has its own distinctive set of symptoms. It’s not always a death sentence for your spuds. In fact, sometimes it’s just a natural phase of their growth cycle. However, it’s essential to identify the cause to address it properly and ensure the health and productivity of your potato plants.

Here are x reasons why potato plants turn yellow:

1. Too Much or Too Little Water

Ever noticed that your potato plants are turning yellow and wondered why? It’s not just you. It happens more often than you think, and there are several reasons. One of the most common, however, is water – either too much or too little of it. 

Just like us, potato plants need water to survive. But did you know that they can drown too? Too much water in the soil can suffocate the roots, leading to yellow leaves. Conversely, too little water can also cause the leaves to turn yellow as the plant starts to dehydrate. 

  • Overwatering: Overwatering can lead to waterlogged soil and root rot, both of which can cause the leaves of your potato plants to turn yellow. If the soil doesn’t drain well, the excess water has nowhere to go, leading to soggy conditions that can damage the roots and stunt growth.
  • Underwatering: On the other hand, if potato plants don’t get enough water, they can become dehydrated. The leaves will start to turn yellow as a distress signal and eventually wilt if they don’t receive adequate moisture.

So, how can you tell if your plants are getting too much or too little water? 

Signs of OverwateringSigns of Underwatering
Yellowing leavesYellowing leaves
Soggy soilDry soil
Root rotWilting plant

“The key to watering potato plants is balance. You want to provide enough water to keep the soil damp, but not so much that it becomes waterlogged. Aim for consistently moist soil, not soggy soil.”

So, the next time you wonder why your potato plants are turning yellow, check their water first. Too much or too little can turn those green leaves yellow in no time.

2. Pests and Diseases

Are you noticing an unusual yellow hue on your potato plants? Don’t fret! This is a common issue that can be attributed to pests and diseases, among other factors. Let’s first explore the various pests and diseases that could be causing this discoloration. 


Potato plants are a favored menu item for certain pests which can result in yellowing of the plants. Let’s take a look at the usual suspects: 

  • Colorado Potato Beetle: Identified by their yellow-orange bodies dotted with black stripes, these beetles can cause serious damage to your potato plants, particularly the leaves.
  • Aphids: These small, soft-bodied insects are known for sucking sap from plants, which can lead to yellowing, particularly if the infestation is significant.
  • Mites: Although tiny in size, mites can cause a big headache for gardeners as they suck the nutrients out of potato plants, leading to yellow and withered leaves.


Several diseases can also cause your potato plants to turn yellow. Here are the key culprits: 

  1. Potato Virus Y (PVY): This viral infection can cause mottling, yellowing and distortion of the leaves.
  2. Verticillium Wilt: A fungal disease that causes yellowing and wilting of leaves, starting from the lower parts of the plant.
  3. Early Blight: Another fungal disease, Early Blight is identified by dark spots on leaves which can then turn yellow and wither.

Now that you are aware of the common pests and diseases that can cause your potato plants to turn yellow, it’s time to consider what you can do about it. 

Knowledge is the first step in prevention and treatment. Understanding potato plant yellowing causes helps you protect your garden and grow a healthy crop.

Stay tuned for the next section where we’ll explore other potential factors contributing to the yellowing of your potato plants.

3. Soil Problems

Imagine this scenario, you’ve put in the time and effort to cultivate your potato crop, only to notice a disheartening sight. The plants are turning yellow. What could be the culprit? Could it be something to do with the soil? Let’s take a deeper look. 

Soil can be a major contributing factor when it comes to your potato plants turning yellow. But what exactly about the soil could be causing this change? There are a few possibilities: 

  • Soil pH imbalance: Potatoes prefer slightly acidic soil, with a pH level of around 5.0 to 7.0. When the pH level is outside this range, it can cause nutrient deficiencies in the plant, leading to yellowing.
  • Overwatering: While potatoes need consistent watering, too much can lead to root rot, which manifests in yellowing leaves.
  • Poor soil drainage: Similar to overwatering, poor soil drainage can cause the roots to become waterlogged, resulting in yellow leaves.

What can we do to fix soil-based issues ? Here are a few solutions: 

Soil pH imbalanceTest the soil pH and amend it according to the results. This may include adding lime to raise the pH or sulfur to lower it.
OverwateringEnsure you’re not overwatering your potatoes. They require about an inch of water per week, including rainfall.
Poor soil drainageImprove soil drainage by adding organic matter or consider planting your potatoes in raised beds.

Still with me? Great, because there’s more to this soil story. 

“Not only does the soil need to be just right in terms of water and pH, it also needs to be rich in nutrients. A lack of nitrogen, for instance, can lead to yellowing leaves.”

So, if you’ve checked your water levels, tested your soil pH, and your potato plants are still turning yellow, it might be time to check the nutrient levels in your soil. 

Checking the Nutrient Levels in Your Soil 

Staring at a garden full of potato plants turning yellow, have you ever wondered, “Why is this happening?” Well, you’re not alone. One of the most common causes is a lack of essential nutrients in the soil. But how can you check this? 

Here’s a simple step-by-step guide: 

  1. Soil Testing: The first step is to test your soil. You can buy a soil testing kit from your local garden store or online, or you can send a sample to a soil testing lab.
  2. Analyze the Results: Once you have the results, it’s time to analyze them. Are there any nutrients lacking? Any imbalances? This clarifies your soil’s needs.
  3. Address the Nutrient Issues: After identifying the issues, it’s time to address them. To replenish nutrients, your soil may need fertilisers or organic materials.

Remember, each type of soil and potato variety may require different nutrient levels. Before making major soil changes, research or consult an expert.

Now, you might be wondering, “What are the essential nutrients for potato plants, and what are their optimal levels?” Here’s a handy table for you: 

NutrientOptimal Level
PhosphorusMedium to High

Maintaining proper soil nutrient levels helps potato plants stay green and healthy. You know what to do, so get to work!

5. Plants Environmental Factors

Ever noticed a sudden change in the shade of your potato plants’ leaves from their usually vibrant green to a concerning yellow? You’re probably wondering, “Why are your potato plants turning yellow?” To keep your potato plants healthy and productive, you must understand this yellowing phenomenon.

There’s a variety of environmental factors that could be behind this unexpected yellowing. Let’s delve into some of these potential causes. 

  1. Improper Watering: Potato plants are particularly sensitive to water levels. Either too much or too little can result in yellowing leaves. Overwatering can lead to waterlogged roots and the onset of root rot, while underwatering can lead to dehydration. Both situations hinder the plant’s ability to absorb necessary nutrients, resulting in yellow leaves.
  2. Inadequate Sunlight: Just like us, plants need sunshine to thrive. Insufficient light can lead to a condition known as chlorosis, which often manifests as yellowing leaves. Is your potato plant getting enough sunlight?
  3. Temperature Fluctuations: Potatoes prefer cooler conditions. If temperatures rise above their comfort zone, it can stress the plant and cause leaf discoloration. Similarly, sudden drops in temperature can also cause yellowing.

How can you tell which of these factors is affecting your potato plants? See the useful table below.

SymptomsPotential CauseSolution
Yellowing of leaves with water-soaked spotsOverwatering/Root rotReduce watering and ensure proper drainage
Yellowing of leaves, especially at the base of the plantUnderwatering/DehydrationIncrease watering, especially during dry spells
Yellowing of leaves with pale veinsInadequate sunlight/ChlorosisRelocate plant to a sunnier spot
Yellowing of leaves with curling or wiltingTemperature fluctuationsMaintain a consistent cool temperature

Keeping a close eye on your potato plants and their environment can help you spot these issues early on and take the necessary steps to rectify them. Remember, a healthy potato plant is a green potato plant!

6. Nutritional Deficiencies

Ever wondered why your potato plants are turning yellow? One of the prime suspects may be nutritional deficiencies. Just like us, plants need a balanced diet to stay healthy. Too little of essential nutrients, and they start showing signs of distress. 

Nitrogen, phosphorus, and potassium, known as the big three, are the plant’s main nutrients. Nitrogen is particularly crucial for leaf growth, while phosphorus and potassium are indispensable for root and fruit development, respectively. 

But what happens if these nutrients are not in the right proportion? Well, the plant can respond in different ways. One of the common signs is yellowing leaves, indicating a lack of necessary nutrients.

Nitrogen Deficiency 

When your potato plants do not get enough nitrogen, the older leaves usually turn yellow first. This happens because the plant moves the available nitrogen to the new growth, leaving the older leaves to turn yellow and eventually fall off. 

Phosphorus Deficiency 

Phosphorus deficiency, on the other hand, often causes the entire plant to turn a darker shade of green before turning yellow. The leaves may also appear purple due to build-up of sugars and anthocyanin pigments. 

Potassium Deficiency 

Lastly, potassium deficiency can cause the edges of the leaves to turn yellow, a condition known as chlorosis. As the deficiency progresses, these yellow areas may turn brown and die. 

So, what can you do to prevent these deficiencies? Let’s look at some solutions. 

  • Test your soil: Regular soil tests can help you understand the nutrient content of your soil and adjust your fertilization strategy accordingly.
  • Use a balanced fertilizer: A balanced fertilizer contains all essential nutrients in the right proportions, helping your plants grow healthy.
  • Rotate your crops: Crop rotation is a great way to prevent nutrient depletion in the soil. Rotating crops helps maintain a balanced soil nutrient profile.

Remember, a healthy plant is a happy plant. Maintaining soil nutrient balance keeps potato plants green and healthy.

7. Fertilizer Burn and Other Chemical Causes

Do you find yourself asking, “Why are my potato plants turning yellow?” It could be due to improper fertilization or exposure to certain chemicals. Potatoes are like humans in a way, they react negatively when overfed or exposed to harmful substances. Let’s investigate these possibilities, shall we? 

1. Fertilizer Burn 

Just like how overeating can make us ill, overfeeding your potato plants with fertilizer can lead to what’s known as fertilizer burn. Simply put, it’s an overdose of nutrients. But how can you tell if it’s fertilizer burn? 

  • Yellowing and wilting leaves: The most common symptom is the yellowing and wilting of leaves, starting from the tips and edges.
  • Brown spots: In severe cases, the leaves might develop brown spots and eventually fall off.

Balance is essential in fertilisation. Quantity doesn’t always imply quality.

2. Chemical Exposure 

Exposure to harmful chemicals can also lead to yellowing in potato plants. Certain pesticides or herbicides, when used excessively or incorrectly, can cause plant stress, leading to yellowing. 

PesticidesYellowing leaves, stunted growth
HerbicidesYellowing and wilting leaves, leaf deformities

Thus, it is imperative to use these chemicals judiciously and follow the recommended application rates and methods. 

So, are your potato plants victims of chemical warfare or victims of their own appetite? Understanding these issues is the first step towards healthier, happier potato plants.

Preventive Measures for Keeping Your Potato Plants Green and Healthy

Ever wondered why your potato plants are turning yellow? You’re not alone. Many gardeners face this concern, but fret not, as we delve into the possible causes and preventive measures to keep your potato plants vibrant and healthy. 

Overwatering: The most common cause is overwatering. Potato plants need a perfect balance of water – not too much, not too little. How do you know if you’re overwatering? The answer lies in the leaves. If they’re turning yellow and the plant looks generally unhealthy, you might be giving it too much water. 

Remember: Potato plants need well-drained soil. Waterlogged soil can cause root rot, leading to yellowing leaves.

Nutrient Deficiency: Another common cause can be a lack of essential nutrients, specifically nitrogen. Potatoes need a healthy dose of nitrogen, potassium, and phosphorus to thrive. If they’re not getting these, the leaves may start to turn yellow. 

NitrogenYellowing leaves starting with the older, lower leaves
PotassiumYellowing at the leaf margins and between the leaf veins
PhosphorusDark-green leaves and stunted growth

So, what can you do to prevent these issues and keep your potato plants green and healthy? 

  • Ensure Proper Watering: As a rule of thumb, potato plants need approximately 1-2 inches of water per week. Don’t forget, the soil should be well-drained.
  • Provide Necessary Nutrients: Use a balanced fertilizer to provide your plants with the nutrients they need. Perform a soil test to determine the specific nutrients your soil lacks.
  • Regular Monitoring: Keep a close eye on your plants. If you notice yellow leaves, take action immediately. Early diagnosis can save your plants.

Remember, you are the best judge for your plants. Every potato variety, every garden, every soil type is unique and may require slightly different care. So, keep your eyes peeled and act promptly if you see any signs of yellowing!


So you see, the yellowing of potato plant leaves isn’t just a cosmetic issue. It’s a warning sign that something is wrong, and if left unaddressed, it could lead to poor growth or even the death of your plants. Whether it’s pests, diseases, nutrient deficiencies, or unfavourable environmental conditions, it’s crucial to identify the problem and take appropriate action. 

In the end, growing healthy potato plants goes beyond just regular watering and sunlight. It requires a keen eye and immediate response to any signs of distress. With the information provided in this article, you’re now better equipped to prevent and troubleshoot why your potato plants are turning yellow. Happy gardening!