Marigold Leaves Turning Purple? (3 Reasons+Solutions)

Marigolds are a popular and versatile annual flower that adds a burst of color to any garden or landscape.

No matter what species of marigold you’re growing, you can always count on these beautiful plants to add some vibrancy and brighten up your living space with their colorful flowers and rich foliage.

That’s why there is hardly anything more disheartening for gardeners or homeowners growing these plants than to see them going through some issues and losing some of their visual appeal.

Especially knowing how much effort it takes to grow them and help them develop into gorgeous ornaments brightening up the entire garden.

One of the most common issues those who grow and care for these plants may face is marigold leaves turning purple.

This can happen for a variety of reasons, some more serious, some rather benign.

Below, I’ll explore each of them and explain what you should do to prevent these problems and how to deal with them once the plant has already been affected.

So let’s dive in and learn about the reasons why your marigold leaves are turning purple!

Reasons Why Your Marigold Leaves are Turning Purple

Marigold plant.

There are several causes that can lead to marigold leaves turning purple, but the most common ones include nutrient deficiency and various fungal infections.

Lack of Nutrients

The main reason why marigold leave may turn purple is the lack of one of the three essential nutrients, magnesium, potassium, or phosphorus.


When a marigold is not receiving enough magnesium, it will not be able to either produce new or maintain the existing chlorophyll.

So, it won’t be able to absorb sunlight and perform photosynthesis properly. As a result, the leaves will lose their bright green color and turn purple.


The lack of potassium won’t impact the plant’s ability to form chlorophyll but will hinder the ability to absorb sunlight and use carbon dioxide and water to produce nutrients.

So, the potassium deficiency will still stop chlorophyll from working and, over time, lead to leaves discoloration and them turning purple.


Without enough phosphorus, a marigold won’t be able to properly develop its roots and stems, so it will have issues absorbing and distributing nutrients.

This may even cause the plant to die, but the first signs will be the stems changing their color to violet and the leaves turning purple.

What to Do?

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The first step in dealing with a nutrient deficiency should always be the analysis of the soil the marigold grows in, so you can identify which particular nutrient is missing.

Once you discover the cause, you can enrich the soil by adding fertilizers rich in the nutrients that are lacking.

Alternatively, you can use more natural methods and mix some organic fertilizers with the soil.

Organic compost will make up for most of the missing nutrients, but here are specific methods for each of them.

Using Epsom salt will increase the level of magnesium in the soil.

To make the soil richer with potassium, you can use seaweed or algae, as well as wood ash or granite dust.

If you’re dealing with a lack of phosphorus, you can use decomposed manure or apply bone meal or superphosphate.

Powdery Mildew

Powdery Mildew on a plant leaf.

Powdery mildew is a dangerous fungal infection that often attacks marigolds, and can, in some cases, lead to a fatal outcome.

The first sign that the plant is infected with powdery mildew is the white layer appearing on the leaves.

Over time, as the infection develops, the leaves will shrink and gradually change their color from green to purple.

The powdery mildew usually appears in conditions when the plant is overwatered and then there’s not enough air circulation around it.

Plus, spores can also spread through the air, so the infected plant may also pose danger to other greenery in your garden.

What to Do?

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Like most fungal infections, powdery mildew is difficult and often impossible to cure.

That’s why you should focus your efforts on prevention and working to eliminate the conditions that are favorable for fungi development.

Individual plants should be planted with a decent amount of space between them, so the air can circulate freely.

If the infection has already taken place, treat the plants with fungicides or use a mix of baking soda and apply if the condition is still not too severe.

White Mold

Another common fungal disease that often attacks marigolds is white mold infection. You can identify it by white buildup forming on the stems and roots of the plant.

Besides the fluffy white mold, the other signs of this infection include tiny black hard formations or sclerotia on the stems and their drying out, as well as wilted leaves that gradually change their color to purple.

As white old spores can live in sclerotia for almost five years, dealing with this infection is a very difficult and often futile task.

When the plant environment is cool and moist, these spores will further develop and grow into mushrooms.

Then, these mushrooms will further spread the spores all over the garden.

What to Do?

Unfortunately, once a marigold gets infected with white mold, there really isn’t much you can do, as this disease is incurable.

So, the best course of action is to discard the entire plants and remove them from the garden.

The discarded plants should be burned or buried. This will at least stop the spread and save the rest of the plants.

When planting marigolds, make sure each plant has enough space, so it can have proper ventilation and maintain dry foliage, as moisture is one of the main preconditions for fungi development.


In most cases, marigold leaves changing color and turning purple is not a reason to panic, as the issue that causes this can likely be dealt with by only a slight adjustment to the care routine.

However, it’s important to learn how to identify the underlying issue causing it, as that will help you determine the proper course of action.

Also, keeping an eye on your plants will help you notice these signs early on when the problem is not that widespread and still easy to contain.

Doing this will ensure that your marigold enjoys healthy growth and can develop to become a beautiful sight for the eyes which is probably the main reason for growing it in the first place.

Melissa Johnson
Melissa Johnson

Hello, I'm Melissa, owner and author of this website. I hope my article was able to help answer your questions. If you want to learn more about me, click the home icon above.

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