Marigold Leaves Turning Purple (5 Reasons Explained)

Marigolds are very beautiful flowers. They have lots of species but every single one of them is gorgeous. If not taken care of properly, marigold plants will show some symptoms.

Marigold leaves turning purple is one of the major indications that your plant is suffering.

There can be many reasons behind the color change of the Marigold leaves. Five major reasons are deficiency of nutrients, white mold infection, powdery mildew, cold soil, and excess sunlight. All these 5 reasons can be taken care of if you identify the reasoning.

Merigold is a spring plant. It doesn’t require a lot of attention to survive. But it still needs to be taken care of when it shows symptoms like color change in the leaves or stems.

In this post, we tried to identify those reasons and provided some easy solutions.

Reasons  Solutions 
Lack Of Nutrient Provide phosphorus, potassium, iron, and manganese.
Powdery Mildew Use fungicide.
Mold Formation Remove the affected plants.
Cold soil Plant the seed in spring.
Balance Of Light More than 6 hours and less than 8 hours. 

Why does Marigold leave Turning Purple?

1. Deficiency of Nutrients

When it comes to the deficiency of nutrients in marigolds then you will need different ways to deal with them. Here are some nutrient deficiencies that can cause the change of color in the leaves of marigolds.  

Magnesium Deficiency

The necessity of magnesium in Marigold leaves lies in the chlorophyll formation. This means when there will be magnesium deficiency, plants will fail to produce new chlorophyll and they won’t be able to maintain the existing chlorophyll. 

As a result, even with all the other possible nutrients, your plant won’t be able to receive sunlight and perform photosynthesis. 

Also, remember that the green color of the leaves comes from the existence of chlorophyll. Due to the lack of chlorophyll, the color of the leaves will turn to Purple from bright green.

You can easily get back the natural green color on the leaves of Marigold by ensuring the magnesium is sufficient. 


There are actually two ways you can deal with the deficiency of magnesium in your marigold plants. The first way is using natural organic compost.

In the case of using organic compost try to make it at home or you can even buy it from any local vendor. 

Do not mix lots of compost at a time with the soil, rather try to use it more frequently. As organic compost holds water for a longer time, it can rot the root if a lot is mixed at a time. 

You can mix the organic compost twice a month with the soil. As it is an organic product there is no definite amount to use rather keep it to your best judgment and don’t go overboard. 

The other way is using Epsom salt. Magnesium sulfate salt is known as Epsom salt.

To balance the chlorophyll through magnesium you can use one tablespoon of Epsom salt for one plant. Then mix Epsom salt with a half gallon of water. 

Apply the mixture to the root of the plant. Also, spread the mixture into the leaves of the plant every two weeks. This way you will see the changes in your medical plants in no time. 

Potassium Deficiency

Potassium doesn’t participate in the formation of chlorophyll. Rather, potassium works as a catalyst that helps the chlorophyll to absorb sunlight.

It also plays an important role in using carbon dioxide and water for manufacturing nutrients. 

We can say that potassium plays an important role in reducing Sugars and starches through photosynthesis using chlorophyll. It also helps in processing oxygen as a by-product of carbon dioxide. 

Whenever there is a potassium deficiency the chlorophyll stops working. As a result, the plant tends to work against forming chlorophyll for further procedure.

This reduces the number of chlorophyll resulting in the change of color of the leaves.

It is safe to say that due to the deficiency of potassium, the plants get weak which results in the loss of the color green and the Marigold leaves tend to turn purple.


Again there are two ways to take care of the potassium deficiency in Marigold plants. Firstly you can use fertilizer which has a high content of potassium.

Either you can choose a fertilizer that is high in potassium or you can buy fertilizers that are formulated especially for Marigold plants.

Both of these products are available in online and offline markets.

Another way to reduce the deficiency of Potassium is to use natural fertilizers. Fertilizers that are made of Seaweed or algae have a high content of potassium. They are very safe to use and don’t have many side effects. 

Also using wood ash or granite dust can be used to provide potassium to the plants. Using these natural fertilizers on a regular basis like once or twice a month by mixing them in the soil helps in the prevention of potassium deficiency. 

Phosphorus Deficiency

Phosphorus is an element that plays a role in the development of roots and stems in marigold plants. Even though leaves are the manufacturer of nutrients for plants, every element goes to the leaf through roots and stems.

The development of roots and stems is equally s to potassium deficiency is the flower dying, the stems turning violet, and the apex of the plant dying. 

Whenever there is Phosphorus deficiency in the Marigold plant it will reflect in the change of color of the leaves.

The colors will turn to a slightly purple color from dark Green. After that, the leaves will start to get blotchy and ultimately will get curly. 

Due to the deficiency of phosphorus, the plants will have late flowering. The effect of color change will also be noticeable in the steps. The same can also get purple or brown patches. 

In an excess deficiency of phosphorus, your plan can even die. Thus it needs to be taken care of as soon as possible. 


There can be two reasons why there is a deficiency of phosphorus. The first one is if the soil is not enriched with phosphorus.

In that case, you can use organic fertilizers. Decomposed manure is a great source of phosphate for marigold plants.

You can also use bone meal or superphosphate to enrich the soil with phosphate. Applying fertilizer once a month is enough to ensure proper nutrients for the plant. 

Another problem that arises is the roots of the plant cannot absorb the phosphorus. In that case, first look at the soil if it is too dry.

Try to use liquid Phosphorus or a mixture of fertilizer with water. Watering the plants regularly helps a lot. 

If watering the plant is not helping, then consult with an agricultural specialist to recognize if your roots have any fungal or bacterial attack. Sometimes these reduce the absorption capability of roots. 

2. Mold Formation

The formation of white mold on the stems and roots of the Marigold plant means it got affected by a fungus named Sclerotinia.

The infection is known as White mold infection. The fungus actually forms a habitat in the damaged part of the leaves and stems. 

Sclerotinia is a fungus that has a black formation. Due to the infection from Sclerotinia, you will also see the leaves are dry and seem like dead leaves. The color will change to either purple or tan. 

Unfortunately, these fungus spores will sustain in your garden for 5 years. It turns out to be a very difficult job to eradicate Sclerotinia from the garden.

They formed their habitat in moist areas and grew into mushrooms. From there the spores spread all over the garden.


Unfortunately, white mold infection doesn’t have any cure. But to keep your garden healthy you need to deal with the situation. 

If the plants are already affected then you need to remove the infected plant from the garden. It is wise to bury or burn sick plants. This will reduce the chances of spreading the spores. 

While planting new Marigold plants tried to keep enough space for ventilation. It is a must to balance the moisture in the garden.

If necessary then reduce the watering for a while without killing the plants. Humidity should be between 30% to 50%. 

There are garden humidifiers available that help to maintain the humidity of the area. Moisture your garden will have, and more Sclerotinia will spread. 

3. Powdery Mildew

Powdery mildew is another deadly fungal infection that causes the change of color in the Marigold plant.

Firstly, you will see a white layer on the leaves. Starting from there the color of the leaves will turn purple. This disease also spreads through spores. 

Especially when there is a deficiency of air circulation the fungal infection increases rapidly. It can also happen when there is excess water and nitrogen. 


To get rid of the Powdery mildew, the best option is to apply fungicides. Also if you apply fungicides during the spring season it will work to prevent powdery mildew.

Set fungi sides you can also use baking soda to kill fungus of powdery mildew. In that case, mix 1 tablespoon of baking soda with water.

Then apply the mixture evenly onto the plants. This will also get rid of the sports that can spread the disease.

4. Cold Soil

Most of the minerals absorbed by marigold plants are from the soil through their roots. But whenever the file is cold or too cold the roots cannot observe bus Minerals and transfer them to the leaves. 

As a result, the leaf cannot process nutrients. Within a few days due to the lack of nutrients, the leaves will turn a purple color. If it continues for a long time, the plant may die. 

Also as a consequence of cold soil, the plants will not have flowers in time. This happens due to the lack of nutrients. Even the plant will also not grow properly let alone produce flower buds.


Marigold plants prefer to grow in the Early Spring when the soil has already started to get warmer. If you are staying in a cold temperature, then you can plant Marigolds in pots and place them inside your room, 

Sometimes the cold soil doesn’t prevail for a long time. Once the soil starts to get warmer the color of the leaves will automatically turn green from purple. 

The best way to avoid such circumstances is to plant the seeds of Marigold during the spring season. Then they will grow full-fledged. 

5. Excess Sunlight

Sunlight is a very necessary element when it comes to planting survival. While performing photosynthesis, plants must have sunlight. Otherwise, it cannot use minerals to produce nutrients. 

But that doesn’t mean more sunlight means more nutrients. Especially in the case of seedlings, excess sunlight is a very pessimistic thing.

Excess sunlight harms the leaves. The damage is reflected in the color change of the leaves. The color of the leaves might change to Purple or red. 

There are some other consequences of excess sunlight. The leaves curl up and turn crispy. Plants already have flowers in them. They will turn brown and die eventually. 


To avoid excess sunlight, you can plant the Marigold seeds in a place where the plant can get only 6 to 8 hours of sunlight. It is better if they receive sunlight for the last part of the day.

If the plant is suffering from excess sunlight then provide shelter over the plant. Continue the Shading until the plant starts to recover. 

Requirements to Grow Marigold Plants

Requirement of Marigold Plants Scale 
pH of soil  6 to 7
Temperature  At least above 40 degrees Fahrenheit.
Watering time In the morning. 
Fertilizer  Must contain phosphorus, potassium, and manganese.


Why Do Marigold Leaves Turn Black?

Marigolds are not lenient toward low-pH soils. This causes manganese or iron harmfulness, which will make leaves brown and dot. In the event that the pH is excessively low, you should alter the dirt with lime for the following year’s plants.

Why Are Marigold Leaves Dying?

Your marigold plant might shrink with an excessive amount of water or excessively little. Remember that a withering marigold plant isn’t guaranteed to constantly require water. Now and again marigold plants shrink when they have an excess of water. Continuously look at the dirt’s dryness to decide whether you ought to give the marigold plant some water.

How Do You Tell If Marigolds Are Dying?

You can recognize an impacted marigold by a mass of slight, upstanding shoots that develop around the foundation of the plant and are typically yellow in variety. The plant’s blossoms are generally disfigured too, taking on a hindered, leaf-like appearance. At last, the marigold might wither and pass on.

Why Do My Marigolds Have Purple Spots?

Two possible explanations are: Your plants may be over-transpiring due to excess moisture and excess heat. You could make sure the soil dries out between waterings just to see if it makes a difference, but if the plant is growing as expected, it should not be a concern. Your plants may have a nutrient deficiency.

How Long Do Marigold Plants Last?

Calendula and Tagetes are annuals, so they just live for one year. Nonetheless, in the event that they are planted early and, deadheaded or routinely cut for the jar, marigolds will blossom for quite a long time, in some cases from May to November. Calendulas will frequently self-sow, giving you more blossoms the next year.

Final Words

Marigold leaves turning purple can raise concern among garden owners. Sometimes they will get depressed thinking that their plants are dying as they were not very attentive.

But the truth is it is not always possible to have a closer look at every single plant in your garden. 

If you see some changes in your Marigold plans especially in the leaves and stems then it is best to take action immediately.

First, try to identify and then take steps likewise.

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