Sometimes you will find parsley leaves turning red losing their bright color. I will explain the causes of parsley leaves turning red. Also, measures to combat and prevent this problem.
Lack of phosphorus can lead to parsley leaves turning red. Improper watering, incorrect soil pH, insect and disease infestation, and environmental stress are the reasons for phosphorus supply disruption.
Continue reading I will explain the cause and solutions for parsley leaves turning red.

Contents
7 Causes Why Do Parsley Leaves Turning Red?
Parsley needs minimum but regular care to grow within your home. If the parsley leaves turning red then it is a signal that there is something wrong and your need to take action.
Here are some of the most common causes of parsley leaves turning red.
Lack of phosphorus can make parsley leaves Red
Phosphorus is one of the fundamental nutrients for any plant. Lack of phosphorus can lead parsley to show symptoms like red leaves. Parsley thrives well in organic-rich soil.
Lack of phosphorus causes the plant to produce a pigment called anthocyanin. This pigment is responsible for the reddening of parsley plant leaves.
There may be many factors interrupting plants to absorb phosphorus from soil. Even if the phosphorus is available in the soil but plant roots are not able to uptake it. In this case, the parsley leaves can turn red.
How to fix
You should not apply phosphorus before confirming the deficiency. You need to do a soil test then consider applying phosphorus if needed. An overdose of phosphorus can cause damage to your parsley.
If you find a lack of phosphorus in the soil then you need to feed your parsley with phosphorus. Bone meal is a good source of phosphorus for the plant. It is slow releasing though but works great.
You can also consider NPK fertilizers available in the market. Here is a helpful and quick video on how you can test soil phosphorus.
Overwatering can Result in parsley leaves turning red
Overwatering disrupts the normal functioning of roots. So, it can not uptake the necessary nutrients for the normal growth of parsley.
Excessive moisture also causes parsley root rot. Because of this disease, your parsley will not be able to uptake phosphorus and other nutrients even if they are available abundantly.
How to fix
If you are confirmed that you have overwatered your parsley then you need to fix this. Do not worry this is very easy to fix.
To fix the overwatered parsley, let the plant pot dry for a few days. Then take out the plant and inspect it carefully.
Remove enough soil so that you can observe the roots. Overwatering may cause root rot. If you find any symptoms of root rot then cut off the infected part.
Then disinfect the root by sprinkling charcoal. Now change the soil and repot in a new container or use the previous one after intense cleaning with hot water.
Compacted Soil
It is normal that your container soil may get compacted over time. Compact soil decreases air permeability. Also, water can not infiltrate through it.
If your parsley does not get enough water and oxygen to its root system. the roots suffocate without receiving the necessary oxygen.
The roots will not be able to absorb the available nutrients. So, lack of nutrients will cause symptoms like leaves turning red, yellow, or brown.
How to fix
Loosen the soil no deeper than 1-1.5 cm and try not to damage the roots close to the surface.
Constant loosening of the soil in the pot destroys compactness in the top layer of the soil. As a result, the top layers of the soil become breathable.
Evaporation of moisture from the layer of soil ground decreases, moisture infiltrates into the root zone. Your parsley will be able to absorb the available nutrients.
Underwatering
Like other plants, parsley does not tolerate drought. If you do not supply the necessary water for functioning the normal physiological process then your parsley will show symptoms.
If there is no water the plant root will not be able to get the nutrients from the soil. Because the nutrients in the soil are only available in water-soluble form.
How to fix
This is obvious that you have to supply enough water to fix this problem. Make sure that there is no stagnant water in the pot. Stagnant water is not good for parsley. You should use settled tap water or filtered water for irrigation.
Let the soil dry a bit then water again. In summer parsley will need more frequent watering than other times. Reduce watering frequency in winter. In this season parsley remains in rest.
Soil pH
Parsley prefers slightly acidic soil. The optimum pH for growing parsley ranges from pH 6.0 to 7.0, this range allows it to absorb the necessary nutrients properly.
Without nutrients, the parsley leaves will turn red.
How to fix
Different plants have their preferred pH ranges. So you have to make sure the mentioned pH for parsley.
To fix the pH of the soil you need to test it. This is very easy to do with a pH test kit.
If you find your soil too acidic (pH below 5.5) which means that you need to deoxidize (increase in pH). To do this, you can use wood fire ashes on top of the soil.
This is also called liming the soil. The use of dolomite (limestone) flour is the most popular method of deoxidizing the soil.
Now if you need to increase soil acidity (decrease the pH level), water with citric acid (lemon juice) works great for indoor plant containers.
Excess light
Like other plants, parsley needs light for photosynthesis. But intensive direct sunlight, the leaves of the parsley turn red and yellow. You will observe this in the spring on old leaves.
How to Fix
In this case, you must keep the pot of parsley in a shady place. During hot sunny days water your parsley more frequently.
Make sure the soil does not get dry (not stagnant water). Also, fertilize with nutrients. Eventually, your parsley will recover.
Parsley Diseases
There are several bacterial and fungal diseases and affect your parsley and cause serious damage. Stunted growth, turning leaves red, yellow, or brown is the most common consequence.
Here are the two diseases that can cause parsley leaves to turn red. Let’s know about them and also how to fight them.
- Stolbur phytoplasma
The causal agent of this viral disease is the parasite Phytoplasma. It causes chlorosis mainly along the edge of the leaves of the lower tiers.
Then the leaves from these edges begin to turn red. This will inhibit the growth of your parsley, the quality of its leaves and roots deteriorates.
- Root Rot
This is a soil-borne fungal disease. It damages the root system and also the crown. The root system can not supply the fundamental nutrients then slowly the plant leaves turn red or yellow.
How to fix
Remove the infected plant parts or the whole plant if the infestation is severe. Overwatering, lack of proper care, are the reasons behind disease outbreaks.
So, the best thing is to prevent them from occurring. You can also use fungicides available in the market to combat these problems.
How to Prevent Parsley leaves from turning Yellow

To avoid the appearance of pests and leaf color change of your parsley you should take the following measures:
- Follow the above-mentioned tips and ensure proper care like watering, top dressing, and ensuring good drainage of water.
- Inspect the plant in a timely manner and remove damaged plants so as not to infect other plants.
- If parsley grows in greenhouse conditions, it is necessary to maintain the air temperature not lower than 20 °С/68°F at night. And during the day 24-26 °С/75.2°F-78.8°F.
- Keep your parsley at a well-ventilated space.
- You should practice crop rotation to avoid disease and pests.
- Make sure the soil and containers is disinfected before planting parsley.
- Disinfect seed before planting. For this purpose, before planting, the seeds are placed for 30–40 minutes in a solution of potassium permanganate and then dried.
- Choose disease-resistant parsley varieties for planting. To do foliar.
- Fertilize the soil with potash and phosphorus.
- Practice the timely thinning of plants; this method will reduce the likelihood of powdery mildew.
- Treat your parsley with soapy water, this will destroy aphids and other pests that weaken plants;
Well-groomed, receiving all the necessary nutrients, parsley almost never gets sick. Leaves turning red is not a cause for panic. Carefully follow the steps and implement the solutions described in this article.