Why Is My Cilantro Turning Red

Cilantro, known for its distinct aroma and refreshing taste, is a cherished herb in numerous cuisines worldwide. It’s typically recognized by its vibrant green leaves.

However, when these leaves start displaying a red tint, it becomes a concern for many gardeners. This guide delves into the reasons behind this color change, ensuring you have a thorough understanding of the phenomenon and can take the necessary actions.

Why Is My Cilantro Turning Red?

When you see your cilantro taking on a reddish hue, it’s natural to be concerned. Here are some reasons why this might happen:

Temperature Stress

Cilantro prefers cooler temperatures. Exposure to very high or very low temperatures can cause stress to the plant, leading the leaves to turn red. Especially during chilly nights or sweltering days, you might notice this change.

Nutrient Deficiencies

Like all plants, cilantro requires certain nutrients to thrive. A lack of essential elements like magnesium or phosphorus can manifest as a color change in the leaves. Red or purple streaks might indicate the plant isn’t getting its needs.

Watering Issues

Both overwatering and underwatering can stress the plant. Overwatered cilantro might develop root rot, a condition where the roots start decaying due to excessive moisture. Underwatered cilantro can become dehydrated, leading to red-tinted leaves.

Diseases And Fungal Infections

Certain diseases and fungi specifically target cilantro. These diseases can cause a range of symptoms, including reddening of the leaves, spots, or other discolorations.

Aging And Natural Progression

As cilantro plants mature and near the end of their lifecycle, it’s not uncommon for the leaves to change color. This can be a natural progression, indicating that the plant is entering its final stages or preparing to bolt (flower and produce seeds).

Understanding these reasons can help in pinpointing the specific cause of your cilantro’s redness and addressing it accordingly.

Whether it’s adjusting your watering routine, providing added nutrients, or simply recognizing the natural lifecycle of the plant, knowing why the change is occurring is the first step to ensuring the health and vitality of your cilantro.

Prevention And Care Techniques

Maintaining a thriving cilantro plant requires a mix of prevention and timely intervention. By understanding its needs and being observant, you can keep most issues at bay.

Here are some care techniques to prevent your cilantro from turning red and ensuring its overall well-being:

Consistent Watering

  • Use the finger test: Insert a finger into the soil up to an inch. If it’s dry, it’s time to water. If it’s moist, wait a day or two.
  • Ensure the pot or garden bed has proper drainage to prevent waterlogged conditions which can lead to root rot.

Nutrient Management

  • Use a balanced, slow-release fertilizer suitable for leafy greens.
  • Observe the plant. If leaves start turning red or show other signs of distress, consider a soil test to determine any nutrient deficiencies.

Temperature Control

  • Plant cilantro in the cooler seasons like spring or fall.
  • If you anticipate a particularly cold night or a scorching day, consider using row covers or shade cloths respectively.

Regular Monitoring For Diseases

  • Check the cilantro regularly for signs of diseases or pests.
  • If you notice any unusual spots or discolorations, identify the problem early and treat it. Fungicides or organic remedies can help, depending on the issue.

Proper Spacing

  • When sowing seeds or transplanting cilantro, ensure adequate space between plants. This allows air circulation, reducing the chances of fungal diseases.


Using a light mulch can help retain soil moisture and regulate soil temperature. It also prevents the soil from splashing onto the leaves, which can spread diseases.

Rotation Planting

  • If you plant cilantro in the same spot repeatedly, the soil might harbor diseases or pests. Rotate where you plant cilantro to prevent recurring issues.

Pruning And Deadheading

  • Regularly remove dead or yellowing leaves. This not only helps the plant focus its energy but also minimizes disease spread.

Preventing Bolting

  • Cilantro can bolt (flower and set seeds) quickly, especially in warmer conditions. Regular harvesting, planting bolt-resistant varieties, and providing shade can delay this process.

By adhering to these prevention and care techniques, you enhance the likelihood of growing robust, green cilantro plants. The key is regular observation and quick action when something seems amiss.

Identification And Treatment Of Cilantro Diseases

Cilantro can be susceptible to several diseases. Identifying these diseases early and implementing effective treatments can save your plants and ensure a healthy harvest. Here are some common diseases that affect cilantro and how to treat them:

Leaf Spot (Bacterial Or Fungal)

  • Identification

Dark brown or blackish spots on the leaves, which may be surrounded by a yellow halo.

  • Treatment

Remove and dispose of infected leaves. Avoid overhead watering, as water can spread the pathogens. Consider using a fungicide or bactericide after consulting with a gardening expert.

Powdery Mildew

  • Identification

A white powdery substance appears on the leaf surface. The affected leaves might turn yellow or brown and fall off.

  • Treatment

Increase air circulation around the plants. Apply a fungicide or a homemade solution (like diluted milk or baking soda spray) to combat the fungus.

Root Rot

  • Identification

The plant appears wilted or stunted. When examined, roots are brown or black and mushy instead of white and firm.

  • Treatment

Ensure proper drainage for the soil. Consider repotting the plant in fresh soil. Fungicides can also help, but it’s crucial to address the root cause, which is typically overwatering.

Damping Off

  • Identification

Seedlings collapse, or their stems appear pinched at the soil line. This disease affects young plants shortly after germination.

  • Treatment

Use sterile soil mixes when starting seeds. Water from below to keep the soil surface dry. A fungicide can help if applied early.

Bacterial Wilt

  • Identification

Sudden wilting of the plant without yellowing. The plant’s vascular system (visible when the stem is cut) may appear dark or brown.

  • Treatment

There’s no effective treatment for bacterial wilt once a plant is infected. It’s best to remove and dispose of the affected plant. Avoid planting cilantro in the same location for a few years.

Aphid-Transmitted Viruses

  • Identification

Yellowing of leaves, stunted growth, and curling or distortion of leaves. Aphids, which transmit these viruses, might be present.

  • Treatment

Control aphid populations using insecticidal soaps, and neem oil, or introduce natural predators like ladybugs. Remove and dispose of severely infected plants.

Carrot Motley Dwarf

  • Identification

A complex disease caused by two viruses, leading to yellowing and bushy or stunted growth.

  • Treatment

Control aphids, as they transmit this disease. Remove and destroy infected plants to prevent spreading.

General Prevention Tips

  • Always use disease-free seeds or seedlings.
  • Practice crop rotation, avoiding planting cilantro consecutively in the same location.
  • Water in the morning so the foliage has time to dry, reducing fungal growth.
  • Keep the garden clean, removing any plant debris or fallen leaves.

By being observant and taking swift action, you can manage and treat many of the diseases that may afflict cilantro. A healthy garden environment, bolstered by good practices, is the best defense against most plant diseases.

Best Practices For Growing Healthy Cilantro

Cilantro, also known as coriander, is a popular herb used in a variety of dishes worldwide. For those looking to cultivate their own cilantro, certain practices can ensure a bountiful and healthy harvest. Here are some best practices to consider:

Choosing The Right Time To Plant

  • Cilantro prefers cooler temperatures. Planting in early spring or late summer/early fall can provide an optimal growth environment.

Soil Preparation

  • Cilantro thrives in well-draining soil. A mixture of garden soil with some compost or organic matter can boost its growth.
  • The soil’s pH level should be between 6.2 to 6.8. It’s worth testing the soil and amending it if necessary.

Sowing The Seeds

  • Sow cilantro seeds directly into the ground; they don’t transplant well from pots to garden beds.
  • Plant seeds about 1/4 inch deep and space them 6-8 inches apart. This spacing helps in air circulation and reduces competition for nutrients.

Consistent Watering

  • While cilantro needs moisture, it’s crucial not to overwater. Keeping the soil moist but not soggy is ideal.
  • Drip irrigation or a soaker hose can be beneficial to provide consistent moisture without wetting the foliage.

Sunlight And Shade

  • Cilantro prefers full sun but can tolerate some shade, especially in hotter regions. A spot that gets 4-6 hours of sunlight daily is optimal.


  • While cilantro isn’t overly demanding, an application of a balanced, slow-release fertilizer at planting time can support its growth.
  • Avoid excessive nitrogen as it can lead to rapid growth with less flavor.

Regular Harvesting

  • Begin harvesting cilantro once it’s about 6 inches tall.
  • Regularly pinching off the top leaves encourages bushier growth and prevents bolting (flowering).

Bolting Prevention

  • Cilantro tends to bolt quickly, especially in hot conditions. Planting in succession (every 2-3 weeks) ensures a continuous supply.
  • Choosing slow-bolting varieties can also help extend the harvest.

Pest And Disease Monitoring

  • Keep an eye out for common pests like aphids or issues like root rot.
  • Introducing beneficial insects like ladybugs can naturally control aphid populations.


  • A thin layer of organic mulch can help retain soil moisture, suppress weeds, and regulate soil temperature.]

Crop Rotation

  • Don’t plant cilantro in the same spot year after year. Rotating helps prevent soil-borne diseases and pests from building up.

By adhering to these best practices, you can enjoy a healthy cilantro crop that’s full of flavor and vitality. Remember, gardening is as much an art as it is a science; be observant, learn from experience, and adjust your practices as needed.


Growing healthy cilantro requires a blend of knowledge and attentiveness to the plant’s needs. From sowing to harvesting, each step has its intricacies.

By understanding the potential challenges and implementing best practices, gardeners can ensure a robust cilantro crop, rich in flavor and vitality.

Ultimately, the rewards of cultivating this aromatic herb are well worth the effort, adding a fresh touch to a variety of dishes and enriching our culinary experiences.

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