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Why Are My Greek Oregano Plant Leaves Turning Yellow?

Updated: April 11, 2022

If you are a gardener who has noticed that your Greek oregano plant leaves are starting to turn yellow, you may be wondering what is causing this problem. Yellowing leaves can be a sign of several different issues, ranging from overwatering to pests or diseases. In this article, we will explore some of the most common causes of yellowing leaves on Greek oregano plants and offer tips for preventing and treating these issues.


One of the most common causes of yellowing leaves on Greek oregano plants is overwatering. Oregano plants prefer dry soil and do not tolerate standing water well. If the soil around your plant is consistently moist or waterlogged, it may be causing the roots to rot and the leaves to turn yellow.

To prevent overwatering, make sure your Greek oregano plant is potted in well-draining soil and that the pot has drainage holes. Water only when the top inch of soil feels dry to the touch, and avoid letting water sit in the saucer under the pot.


While overwatering can cause yellowing leaves, underwatering can also be a culprit. If your Greek oregano plant is not getting enough water, its leaves may start to turn yellow or even brown.

To prevent underwatering, make sure you are watering your plant regularly and deeply enough to reach the roots. Water when the top inch of soil feels dry, and make sure the water penetrates all the way through the potting mix.

Nutrient Deficiency

Greek oregano plants require specific nutrients to grow and thrive. If they are not getting enough of these nutrients, their leaves may start to yellow or even turn brown.

The most common nutrient deficiency for oregano plants is nitrogen. Nitrogen is essential for green leafy growth, and a lack of it can cause the leaves to lose their vibrant green color. If you suspect your plant has a nutrient deficiency, you may want to consider fertilizing with a balanced fertilizer that contains nitrogen, phosphorus, and potassium.

Pests or Diseases

Yellowing leaves on Greek oregano plants can also be a sign of pests or diseases. Common pests that can affect oregano plants include spider mites, aphids, and whiteflies. These pests can suck the sap from the leaves, causing them to turn yellow and eventually die.

Diseases such as root rot, powdery mildew, and bacterial leaf spot can also cause yellowing leaves on Greek oregano plants. These diseases are often caused by overwatering or poor air circulation.

To prevent pests and diseases, make sure your Greek oregano plant is getting enough light and air circulation. Check the plant regularly for signs of infestation or disease, and treat promptly with an appropriate insecticide or fungicide.


Yellowing leaves on Greek oregano plants can be a frustrating problem for gardeners. However, by understanding the common causes and taking steps to prevent and treat them, you can help your plant stay healthy and vibrant.

Remember to always check your plant regularly for signs of stress, including yellowing leaves. With proper care and attention, your Greek oregano plant will continue to thrive and provide you with fresh herbs to enjoy in your cooking.


Can I save my Greek oregano plant if its leaves have already turned yellow?

It depends on the cause of the yellowing. If it is due to overwatering or underwatering, you may be able to save your plant by adjusting its watering schedule. If it is due to pests or diseases, you may need to treat the plant with an insecticide or fungicide.

What kind of soil should I use for my Greek oregano plant?

Greek oregano plants prefer well-draining soil that is slightly alkaline. You can use a high-quality potting mix with added perlite or sand to improve drainage.

Can I grow Greek oregano indoors?

Yes, Greek oregano can be grown indoors as long as it has access to plenty of light and air circulation. Consider placing your plant near a sunny window or under a grow light.