Why Did My Mint Leaves Turn Purple – How to Fix(6 Reasons)

The purple coloration of mint leaves is usually caused by low temperatures, nutrient deficiencies, herbicide damage, root rot, pests, or a genetic mutation. Here’s how you can address and fix these issues to restore the green hue of your mint leaves.

Mint plants are treasured for their vibrant green leaves and aromatic properties, making them a popular choice in gardens and culinary creations. However, finding your mint leaves turning purple can be perplexing and may signal an underlying issue. We will explore six reasons why your mint leaves may have turned purple, and provide effective solutions to help you revive and maintain the healthy green appearance of your mint plants.

By understanding and addressing these factors, you can ensure the continued vitality and appeal of your mint garden.

Reason 1: Nutrient Deficiency

Plants require a balanced and sufficient supply of nutrients to grow and thrive. When your mint leaves turn purple, it could be a sign of nutrient deficiency. Here are some possible reasons and remedies to consider:

Lack Of Essential Nutrients In Soil:

  • Nitrogen deficiency: A lack of nitrogen can cause the leaves to turn purple. Nitrogen is vital for leaf development and overall growth.
  • Phosphorus deficiency: Insufficient phosphorus can also lead to purple discoloration. Phosphorus is important for energy transfer and root development.
  • Potassium deficiency: Without enough potassium, the mint leaves may exhibit purple coloration. Potassium is necessary for overall plant health and vigor.

Imbalanced Nutrient Ratio:

  • Ph imbalance: An overly acidic or alkaline soil can affect nutrient availability, leading to purple mint leaves. Ensure the soil ph is within the appropriate range for mint plants (6.0-7.0).
  • Imbalanced nutrient ratio: An inadequate balance of nutrients in the soil can cause nutrient deficiencies, resulting in purple foliage. Conduct a soil test to determine the nutrient levels and adjust accordingly.

Remedies To Correct Nutrient Deficiency:

  • Fertilize appropriately: Use a balanced fertilizer or organic amendments to provide the necessary nutrients to the soil. Choose a fertilizer with an npk ratio suitable for mint plants.
  • Soil amendments: Address nutrient deficiencies by incorporating compost, well-rotted manure, or specific nutrient supplements recommended for mint plants. These amendments can improve the nutrient content and balance in the soil.
  • Test and adjust: Regularly test the soil to monitor nutrient levels and adjust fertilization accordingly. Maintain optimal nutrient balance to promote healthy growth and prevent nutrient deficiencies.

Remember, nutrient deficiencies can also be indicative of underlying soil and plant health issues. If your efforts to correct the nutrient deficiency do not yield the desired results, it is recommended to consult with a gardening expert or horticulturist for further guidance.

As an Amazon Associate we earn from qualifying purchases.

Reason 2: Soil Ph Imbalance

Acidic Soil Conditions

  • Mint plants prefer a slightly acidic soil with a ph level between 6.0 and 7.0.
  • When the soil becomes too acidic, with a ph below 6.0, it can cause the mint leaves to turn purple.
  • High levels of acidity in the soil can also impact the plant’s ability to absorb essential nutrients.
  • To identify acidic soil conditions, you can use a soil ph testing kit available at garden centers.
  • If your soil is too acidic, you can neutralize it by adding lime or wood ash to raise the ph level.

Alkaline Soil Conditions

  • On the other end of the spectrum, alkaline soil conditions with a ph above 7.0 can also cause mint leaves to turn purple.
  • Alkaline soil can inhibit the plant’s ability to absorb nutrients like iron, leading to purple discoloration.
  • You can check the ph level of your soil using a soil ph testing kit to determine if it is too alkaline.
  • If your soil is too alkaline, you can lower the ph level by adding sulfur or using acidic organic matter like peat moss.

Adjusting Soil Ph Levels For Healthy Mint Plants

  • To create optimal growing conditions for your mint plants, it’s crucial to adjust the soil ph levels.
  • You can make the following adjustments to balance the soil ph for healthy mint plants:
  • Add lime or wood ash to raise the ph level if your soil is too acidic.
  • Incorporate sulfur or acidic organic matter like peat moss to lower the ph level if your soil is too alkaline.
  • Follow the instructions on the product packaging for proper application rates.
  • Regularly monitor the soil ph levels to ensure they remain within the ideal range for mint plants.
  • Providing the correct ph balance in the soil will help prevent purple leaves and promote healthy growth for your mint plants.

Remember, maintaining the right soil ph is vital for the overall health and vibrancy of your mint plants. When acidity or alkalinity levels go awry, it can lead to problems like purple leaves. By adjusting the soil ph, you can ensure your mint plants thrive and showcase their beautiful green foliage.

Why Did My Mint Leaves Turn Purple – How to Fix(6 Reasons)

Reason 3: Environmental Factors

Mint plants are sensitive to their environment and can exhibit color changes due to various factors. Understanding and managing these environmental conditions can help prevent your mint leaves from turning purple. The following are the major environmental factors that can affect your mint plants:

Extreme Temperature Fluctuations:

  • Sudden temperature changes, especially cold snaps, can cause the leaves of mint plants to turn purple.
  • If the temperature drops below 50°f (10°c) or rises above 90°f (32°c), your mint plants may struggle and develop purple leaves.
  • Extreme temperature fluctuations can disrupt the plant’s physiological processes, leading to pigmentation changes.

Excessive Sunlight Exposure:

  • Mint plants prefer partial shade and can become stressed when exposed to direct sunlight for extended periods.
  • Too much sunlight can result in scorched leaves and a purple tint.
  • In intense sunlight, the plant may produce excess anthocyanin, a purple pigment, as a protective mechanism.

Managing environmental conditions for mint plants:

  • Choose a suitable location for your mint plants, providing them with some shade during the hottest parts of the day.
  • If you live in an area with extreme temperature variations, consider growing mint in containers that can be moved indoors during extreme weather conditions.
  • Provide a well-draining soil mix that retains moisture without becoming waterlogged.
  • Regularly monitor the temperature and adjust as needed by providing shade or relocating the plants.
  • Mulching can help regulate soil temperature and moisture levels. Apply a layer of organic mulch around the mint plants to conserve moisture and control temperature fluctuations.
  • Regular watering is crucial for mint plants, especially during hot and dry weather conditions. Be cautious not to overwater, as excessive moisture can lead to root rot.

By understanding and addressing these environmental factors, you can maintain healthy and vibrant mint plants with green leaves. Keep an eye on temperature fluctuations, provide suitable shade, and ensure adequate moisture levels to prevent your mint leaves from turning purple.

Reason 4: Pests And Diseases

Mint plants are prone to pests and diseases, which can lead to changes in leaf color, including turning purple. Identifying and addressing these issues is crucial for the health and vitality of your mint plant. The following are common pests and diseases that can cause your mint leaves to turn purple, along with tips on how to treat them.

Infestation By Aphids Or Spider Mites:

  • Aphids or spider mites are small insects that can infest mint plants.
  • Symptoms of infestation include distorted leaves, sticky residue on the leaves, and visible pests.
  • Treat aphids or spider mites by spraying your plants with a mixture of water and insecticidal soap, following the instructions on the soap’s label.
  • Another natural remedy is to introduce ladybugs, which are natural predators of aphids and spider mites, into your garden.

Fungal Or Bacterial Infections:

  • Fungal or bacterial infections can also cause mint leaves to turn purple.
  • Common fungal infections include powdery mildew and rust.
  • Bacterial infections can cause leaf spots or blights.
  • Remove infected leaves immediately to prevent the spread of the infection.
  • Treat fungal infections by applying a fungicide that is safe for edible plants, in accordance with the product’s instructions.
  • For bacterial infections, avoid overhead watering and ensure good air circulation around the plants to minimize moisture and humidity levels.

Identifying And Treating Pests And Diseases In Mint Plants:

  • Regularly inspect your mint plants for signs of pests and diseases, such as discoloration or visible insects.
  • Early detection is key to preventing the spread of pests and diseases.
  • Remove any infected or infested leaves to prevent further damage.
  • Practice good gardening hygiene by keeping the area around your mint plants clean and free from debris.
  • Avoid overwatering or overcrowding your plants, as these conditions can promote the growth of pests and diseases.
  • Consider planting mint in containers or separate areas to prevent the spread of diseases to other plants.

Remember, maintaining a healthy garden requires proactive pest and disease management. By promptly identifying and treating infestations and infections, you can ensure the vibrant green color of your mint leaves and enjoy its fresh flavor for culinary delights.

Reason 5: Overwatering Or Underwatering

Mint plants are quite sensitive to water levels, and improper watering can have detrimental effects on their health and appearance. Both overwatering and underwatering can cause various consequences for your mint plants. Understanding these consequences and implementing proper watering techniques are crucial for maintaining the health and vigor of your mint leaves.

Consequences Of Overwatering Mint Plants:

  • Yellowing leaves: Overwatering can lead to yellowing of the mint leaves due to the prolonged saturation of their roots. This is a sign of root rot, where the roots become waterlogged and lack oxygen.
  • Wilting: Surprisingly, overwatering can cause mint leaves to wilt. The excess moisture prevents the roots from absorbing essential nutrients and oxygen, resulting in wilting and drooping leaves.
  • Fungal diseases: Excessive moisture can create a hospitable environment for fungi and other pathogens. This can lead to the development of various fungal diseases, such as powdery mildew and root rot, affecting the overall health of your mint plants.

Consequences Of Underwatering Mint Plants:

  • Leaf discoloration: Underwatered mint plants may exhibit a purple coloration on their leaves as a survival mechanism. The plant produces anthocyanin pigments in response to stress and water scarcity, resulting in purple foliage.
  • Stunted growth: Insufficient water supply can stunt the growth of mint plants. Without proper hydration, the plant struggles to carry out essential metabolic processes, leading to stunted growth and poor development.
  • Prone to pests: Underwatered mint plants are more susceptible to pest infestations. When stressed, the plants produce chemical signals that attract insects and other pests. These pests may further damage the already weakened mint plants.

Proper Watering Techniques For Mint Plants:

To prevent the adverse effects of overwatering and underwatering, it’s important to establish proper watering techniques for your mint plants. Follow these guidelines:

  • Allow the top inch of soil to dry out between watering sessions.
  • Water in the early morning to prevent excess moisture accumulation and give the plants ample time to dry before nightfall.
  • Avoid overhead watering as it can contribute to fungal diseases. Instead, direct the water at the base of the plant near the roots.
  • Use well-draining soil that allows excess water to drain away, preventing waterlogged roots.
  • Adjust the frequency of watering based on weather conditions. Mint plants may require more water during hot and dry periods.

By recognizing the consequences of both overwatering and underwatering, and implementing proper watering techniques, you can ensure the health and vibrancy of your mint plants. Remember, maintaining an ideal balance of moisture is key to cultivating thriving mint leaves.

Reason 6: Genetic Factors

Mint plants, like any other living organisms, exhibit natural variations due to their genetic makeup. Different mint varieties have specific traits that can influence their leaf color. Here are some key points to consider regarding genetic factors and mint leaf color:

  • Natural variations in mint leaf color: Mint plants possess natural variations in leaf color, including purple hues. This variation is primarily determined by genetic factors unique to each mint variety.
  • Cultivar-specific traits: Each mint cultivar has specific traits that contribute to its leaf color. Some mint varieties naturally produce purple leaves, while others may show purple pigmentation due to a genetic mutation.
  • Selecting and caring for the right mint variety: If you specifically want to avoid purple leaves, select mint varieties known for their green leaves. Different cultivars have their own unique leaf color, so it’s essential to research and choose the right mint variety for your preferences.

Understanding genetic factors that influence mint leaf color can help you select the appropriate mint variety and care for it accordingly. Remember to cater to your specific preferences by choosing the mint variety that aligns with your desired leaf color.

Frequently Asked Questions On Why Did My Mint Leaves Turn Purple – How To Fix(6 Reasons)

Why Are My Mint Leaves Turning Purple?

Mint leaves turning purple can be caused by various reasons such as nutrient deficiencies, cold temperatures, or herbicide damage. It could also be a natural response to stress or a sign of disease. Proper care, including providing adequate sunlight, water, and well-drained soil, can help resolve this issue.


To sum up, the discoloration of mint leaves into purple can be discouraging for garden enthusiasts. However, understanding the reasons behind this issue allows for effective solutions. Firstly, excessive sunlight exposure can cause purplish discoloration, so it’s important to provide partial shade to your mint plants.

Secondly, nutrient deficiencies, particularly phosphorus or magnesium, should be addressed through proper fertilization. Thirdly, temperature fluctuations and cold weather can lead to purple leaves, so maintaining consistent temperatures is essential. Fourthly, overwatering or improper drainage can create stress and induce leaf discoloration.

Adjusting watering practices accordingly contributes to healthier plants. Additionally, insect infestations, such as spider mites or aphids, need to be promptly addressed using organic pest control methods. Lastly, selecting appropriate mint varieties suitable for your specific climate and growing conditions contributes to the prevention of leaf discoloration.

By implementing these strategies, you can enjoy vibrant, green mint leaves and flavorful herbs in your garden.

© 2024 Lotusmagus.com. All rights reserved. This content is protected by copyright. Visit Lotusmagus.com for more information.

Amelia Clark

I'm Amelia Clark , a seasoned florist and gardening specialist with more than 15 years of practical expertise. Following the completion of my formal education, I dedicated myself to a flourishing career in floristry, acquiring extensive understanding of diverse flower species and their ideal cultivation requirements. Additionally, I possess exceptional skills as a writer and public speaker, having successfully published numerous works and delivered engaging presentations at various local garden clubs and conferences. Check our Social media Profiles: Facebook Page, LinkedIn, Pinterest, Youtube, Instagram Tumblr

Recent Posts