If you’ve noticed your Oregano leaves turning brown, don’t worry, you’re not alone. Even though there can be several reasons why this could be happening, here I will help you find the exact solutions to fix the problem—no wonder anyone could get frustrated over homegrown Oregano at home if it turns brown.

You’re in the right place if you’re wondering why your once healthy and green leaves are turning brown. In this article, we’ll explore seven possible reasons ‘why are my oregano leaves turning brown,’ along with helpful tips on how to fix those brown leaves, so your oregano plant can return to its healthy, green state.

7 Reasons Why My Oregano Leaves Turning Brown

Oregano Leaves Turning Brown
Oregano Leaves Turning Brown

If you feel worried about brown spots on oregano leaves or the Oregano leaves turning brown, check these seven possible reasons to find out the actual culprit before you start and try to fix the issue.

Environmental Stress

There can be a few Environmental stressors in your region, like extreme temperature fluctuations or humidity levels, which may lead to brown spots on oregano leaves. If this is the case, you should keep your oregano plant in an environment with consistent temperature and humidity to avoid stress.

Inadequate Sunlight 

I hope you know that Oregano needs a lot of sunlight to grow. If you’re not giving sufficient light to your plants, it can again lead to brown leaves. According to the University of Minnesota Extension, most herbs like Oregano needs at least 6 hours of direct sunlight daily to thrive. So ensure you also adhere to this by relocating your plant if required.


As per the University of Illinois Extension, Overwatering can lead to root rot, causing brown leaves. Thus, you need to provide well-draining soil for the Oregano. One of the common reasons for brown spots on oregano leaves is said to be overwatering. I highly advise you to water your oregano plants only when the top inch of soil feels dry.


On the other hand, if you’re not providing sufficient water to your oregano plant, it will develop brown leaves again. American Journal of Plant Sciences says that Oregano may go into a state of drought stress if it becomes too dry, leading to brown spots on the leaves. 

Nutrients Deficiency

Another potential reason your Oregon plant is turning its leaf color crown could be directly related to its nutrients or soil quality. I don’t need to tell you that Oregano also needs a proper balance of nutrients to thrive and grow. Therefore if your oregano plant isn’t getting enough nutrients, it can lead to brown leaves.

Pest Infestation Or Disease

Maybe your Oregano plant is already affected by insects like spider mites, aphids, or more. Sometimes diseases like powdery mildew cause brown spots on Oregano leaves too. This is why it is recommended to take preventive measures that can help you avoid pests and diseases. 


Lastly, your oregano plant may also color its leaves brown due to aging. As oregano plants age, their leaves may turn brown and fall off naturally. Since this is a natural part of the plant’s life cycle, there’s not much you can do as well as you shouldn’t worry unless the plant dies. 

Also Read: What does oregano look like when it sprouts?

How To Fix Oregano Brown Leaves?

When you notice down lives on your oregano plant, you already know it’s not a good or healthy sign. It usually indicates something is wrong with your plant for sure. Therefore, before you get worried about this issue and try to fix anything right, here is a systematic approach. Make sure to follow the advice given below carefully to fix Oregano brown leaves as soon as possible.

  1. As Old Farmer Almanac suggests, water oregano when its top inch of soil feels dry; make sure not to let the soil dry out completely. As I told you earlier, overwatering and underwatering can cause leaves to turn brown.
  2. UMN recommends providing at least six hours of direct sunlight daily to herbs like cilantro. Thus, If your plant is not getting enough light, consider moving it to a sunnier location.
  3. First, purchase a pH testing kit at your local garden center or online to check your soil quality to determine its pH. If you find the pH, you need to adjust it by adding lime to the rail where pH or sulfur to lower it.
  4. If you notice any pests on your plant, you can use a natural insecticide to eliminate them. As per The Journal of Insect Science, you can use neem oil as it is an effective natural insecticide for controlling herb pests.
  5. Lastly, prune your oregano plant in the spring before new growth appears. You need to cut back about a third of your plant. Put your focus on removing any dead or damaged leaves & stems.

9 Things Oregano Plants Need

  1. Firstly, you must provide your oregano plant with at least 6 hours of direct sunlight daily to make them thrive and grow properly. 
  2. It is essential to provide consistent moisture to your oregano plants to help them grow. Make sure not to over-water it. 
  3. Only harvest your Oregano by the top third of the plant to avoid damaging it.
  4. I will advise you always to pick a good location to plant your Oregano that receives full sun and partial shade with well-draining soil. You can plant it indoors in a pot or outdoors in a garden. 
  5. Always test the soil pH before planting Oregano, as the preferred pH is between 6.0 and 8.0. 
  6. Adding some fertilizers occasionally every few weeks is advisable to help it grow. 
  7. Never mind adding a layer of mulch around the oregano plant base,, which will help you retain moisture for a more extended period, especially on hot days, while keeping the soil temperature stable. 
  8. It is essential to always plant your Oregano at the right time,, usually ‘spring after the last Frost has passed.’ 
  9. Just like any other plants, oreganos are known to benefit from regular pruning but use a clean and sharp shear.

Related Articles: What do oregano seedlings look like? [3 core signs to understand]


Why Does My Oregano Have Brown Spots?

One of the most common causes is a fungal infection known as brown spot fungus. Several factors, including high humidity, poor air circulation, and over-watering, can cause this.

How Do You Treat Brown Spot Fungus On Plants?

As I told you, remove any affected leaves or stems from disposing of them and prevent the spread of the fungus to other plants. Alternatively, you can treat the remaining plant with a fungicide available at most garden centers or nurseries. Make sure you’re paying attention and following the instructions carefully. 

Why Are My Cuban Oregano Leaves Turning Brown?

One possibility is that your Cuban oregano plant is not getting enough water or is getting too much water. Cuban Oregano prefers well-draining soil and does not like to be overwatered. Or your plant lacks adequate sunlight. Cuban Oregano likes bright, indirect light and may develop brown leaves if it is in a location that is too shady.


I tried my best to give you all the information you needed on why my oregano plant leaves are turning brown. If you find this article helpful, then consider sharing it. Here, you learned several reasons for Oregano leaves turning brown: pest infestations, diseases, overwatering, improper irrigation, inadequate sunlight, and many more.

Depending upon the issue, you should take action in a systematic approach. Also, wear proper protective gear when pruning shear or fungicide. Sharing our article will help many people understand why are their oregano leaves turning brown or might turn brown if something goes wrong. Do check our other helpful guide on oregano planting and care. See you in the next post, till then take care and goodbye.

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