Why Are Mint Leaves Turning Purple?

Last Updated on August 4, 2022 by Stephanie

Mint plants are often associated with freshness. The leaves are wonderful to incorporate into a range of dishes that are delicious and also in delicious drinks such as Mojitos and teas.

It can be a bit depressing to notice that your plant is changing from bright green to a new purple.

There are a variety of reasons the leaves of mint turn purple. learn more about how you can keep your beautiful plant healthy and green!

The reason why the leaves of mint turn purple because they are grown in soil that is deficient in the mineral phosphorus. Bone meal or fertilizer may be used to boost the levels of phosphorus. Another reason for the color of mint changing is excessive watering. Mint plants do not require much water to thrive, so its easy to over-water the plants.

Mint plants require minimal maintenance once youve identified the root cause of your plants purple funk, its simple to fix the issue.

Lets look at the reasons that could be behind the leaves turning purple. You can restore your plant to its bright green self within a matter of minutes.

Causes of Mint Leaves Turning Purple

Below, youll discover a myriad of possible reasons for those dreadful purple leaves. All of them can be solved easily.

Theres no reason to be discouraged Ive got you covered with solutions to every one of these issues!

Lacking Nutrients

Mint has a rich soil that has an acidity range of 6.0 to 7.0. Mint requires a high level of nitrogen, phosphorus, and potassium.

The cold soil, or the soil that is too moist could hinder the plants to effectively absorb nutrients.

So, even when nutrients are present however, the plant cant profit from these nutrients!

Other reasons that could prevent the mints ability to absorb nutrients are excessive soil acidity or excessive iron levels within the soil.

A deficiency in nutrients will cause a plant to struggles to survive and will be evident by changes in the size and capacity to sustain leaves, and in the health and color of the leaves themselves.

Source: Taylor and Francis Journals

How do you fix a deficiency of nutrients

You can give your minty friend a healthy assistance by conducting an analysis of the soil.

If your phosphorus levels have dropped, it is possible to increase the levels by including bones meal or compost, or manure.

Check that the soil conditions allow the mint plants to fully get the nutrients it needs!

Make sure youre not overwatering your plant , and then move it to a cooler location in case the soil is too cold.

If the soils pH is low, increase it using lime. Maintaining the soils pH within 6.0 and 7.0 is also a good way to ensure that iron levels remain at a high level.

Source: College of Agriculture and Life Sciences- The University of Arizona


Utilizing a lot of fertilizer may appear like a guaranteed method to care for the mint plants.

However, it is possible to have too many good things. Overuse of fertilizers can lead to significant issues.

A lot of fertilizer can cause a plant to grow quickly, but the roots of the plant dont develop fast enough to compensate.

In the end, the plant suffers as the roots arent able to adequately supply the entire plant with nutrients and water.

The result is that you end up with a plant that is deficient in minerals and vitamins, also called a very unhappy plant!

Mint is more likely to be extremely sensitive to this deficiency of nutrients. Mint may show symptoms like the leaves becoming darker or turning purple.

This can also result in the mint plants becoming less fragrant and less fragrant, something we would like not to do at any cost!

flowering mint variety

How to Fix Problems With Overfertilization

If your plant is being over-fertilized There are simple solutions. First, put an end to fertilization right away! Give it at least a month before you think about feeding it with food.

If you see fertilizer in your soil, remove it immediately to reduce how much fertilizer you can offer the mint plant. Take away any damaged or broken leaves and stalks so that your plants roots are able to provide nourishment to the remainder of the plant.

Source: UCCE Master Gardeners of El Dorado County


Mint isnt well-known as an avid sun worshipper. While it appreciates a little small amount of light, putting the mint in intense direct sunlight is the recipe for a unhappy plant.

If you can maintain the soils moisture with regular irrigation, it could be able to thrive in a sunny location.

But, mint plants prefer to live in partial shade. In contrast to most culinary herbs, mint thrives in areas of shade.

Plants with sunburned skin struggle maintain their natural green color usually turning brown and brittle due to the harm theyve suffered.

How to Fix a Sunburnt Mint Plant

Pick a spot close to a window that is sunny for the mint plants, however be sure that its not in direct sunlight for long periods in a row.

Make sure that its receiving plenty of water when its exposed to sunlight.

Be aware of the way that sunlight is changing throughout the year. You may have to relocate your plant in certain months when it suddenly gets too much sun.

Insufficient Light

While Ive mentioned before that mint plants are prone to get a little stale and fight with the heat, its also crucial to not strip the plants of sunlight altogether. A dark corner in the home will not make the leaves to stay green for very long.

Without light plants arent able to perform photosynthesis. This process of biological reproduction helps keep the leaves green. There is no sun, there are and no leaves!

How to Fix Lighting Problems

Maintain mint plants in bright spaces and keep them away from dimly illuminated enclaves or dark spaces.

Its also required to change the location of your plant periodically, to ensure that its not left in darkness!

If you dont have a well illuminated area, you might think about shifting your mint plant to an area that is more light during the daylight hours and then putting it back in its normal place at night.

Its also important to keep to your mind the fact that synthetic lighting can aid plants in areas which dont receive enough sunlight.

Lighting specifically designed for the growth of plants can be a great alternative!

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Insect Infestation

Insects can be a nuisance problem-makers when they are trying to maintain the well-being of your mint plant.

Spider Mites, Thrips, and Aphids all like to make their home on the leaves of your favorite plant.

While this might be a good thing for mints, it does not do mints health any favours.

The insects tendency to eat plants means that they deprive your mint of essential nutrients, which can lead to the decoloration of your leaves and overall unhealthy conditions.

How to Fix Insect Infestation

Insecticides derived from plants can be an effective tool to remove unwanted pests off the mint leaves.

They also have the benefit of not causing damage to the plant itself. You can use garlic oil or rosemary oil.

Rubbing alcohol on your plants can eliminate unwanted pests, however it can be quite drying, so apply be cautious.

Sometimes, simply applying water to the plants could suffice to ward off unwanted critters.

Overwatering or Underwatering

Like other plants, mint requires plenty of water, but not too excessively. It is simple to pour water on your mint plant particularly if you not have watered it for a couple of days.

Unfortunately, this can have the result of encroaching on the plant, and flushing precious nutrients out of the soil.

A lot of water for a long time can lead to the rotting of roots. Yikes!

When the ground is too dry, the water will not be capable of making it through the mints root systemand once again, its going to struggle to obtain the nutrients it requires.

The result will be a dry minty feeling and dry.

Insufficient nutrients, caused by excessive watering or submerging, is likely to cause significant issues.

The mint will be struggling to survive and its extremes (its leaves!) are the first to be that will be affected. In most cases, they change color, shrink or even fall off.

How to Fix Overwatering or Underwatering

The soil around your mint plant needs to be moist, but not damp. If the soil on top seems squishy, then that youre overwatering your plants.

An effective way to determine the level of moisture below the soil surface would be to insert your fingers into soil in a small way. It should also be moist, not wet , and not dry.

Do not pour water directly on plants leaves since it could cause damage directly to the leaves.

You May Also Enjoy: Why Is My Mint Turning Brown? (And How to Fix It)

Poor Drainage

Mint plants must be placed in pots that can drain effectively. In nature, theyre often located along the banks of rivers, a spot that provides them with a excellent natural drainage.

At home we do not usually have the resources to replicate the natural drainage system. However, we can ensure that the pots we choose to use to grow our mint plants are very close.

The problem is that mint thrives on water, however without proper drainage , the roots will begin to rot and the health of the plant will decline.

This can cause changes in the coloration of leaves and makes the plant overall less robust.

Solutions to Problems with draining

All soils are not created equally, and some do have less drainage than other. Be sure to use the right mix of sand and soil, or perlite, to increase drainage of your pot.

Pots must have drainage holes in the bottom. They should also be big, at a minimum of 10 inches (25.5 cm) deep.

Temperature Changes and Time of Year

While these elements might not affect your indoor plants as much as outdoor plants the changes in temperatures and the season will affect the appearance and health the appearance of plants.

Mint plants prefer temperatures that is between 55-70degF (13-21degC). In winter and cold seasons, your plants may be affected by the cold exactly as you do, rendering them ineffective at absorbing the soils nutrients in the same way.

In hot temperatures, and in the summer heat, they could be prone to drying out and wilting out.

Any or both of them could lead to plants leaves becoming affected and changing the color.

How to Fix Temperature Problems

Monitor temperatures to determine if they fall to below 55degF (13degC) or go above 70degF (21degC).

In the event of cold temperatures, think about shifting your plant away from cold windows and doors, and placing it in an area that is warmer.

If needed an indoor heater can be used to increase temperatures, but be sure not to place the heater too near the plant you want to keep.

If its too hot then allow your mint to cool down by shifting it to a cooler region.

It is an ideal idea to keep windows shut throughout the daytime (shutting the hot air away) and then open them at night to let more fresh air in.


Dont be worried when the leaves of your mint plant have turned purple. Follow the tips above to bring your plant back to health within a matter of minutes!

Have you experienced issues in the form of your leaves changing color? What were you able to do to get rid of the issue?



Went from an inexperienced gardener to a half-decent one over 10+ years. I cover anything from general indoor plant guides and lawn care, to succulents and flowers. Super happy to share my tips and tricks with you :)