Black Spots on Oregano Leaves: Reasons and Remedy


The oregano leaves are great medical herbs. They’re also super easy to grow but from time to time you might see some black spots on them.

It’s a sign that’s telling you that something went wrong. And it needs your immediate attention.

So, what causes the black spots on oregano leaves and how can you make them go away?

Well, there are a number of reasons for which your oregano leaves might suffer from a case of black spots. And as the problems are different so are the solutions.

You see, you need to take a different approach to each of the problems. So, why don’t we take a look at all the problems and solutions in detail?

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Photo of Italian Oregano
Photo by Jinlide

Reasons and Solutions for Black Spots on Oregano Leaves?

The thing about gardening is that there can be many things that can cause your plants to be unhappy. So, you always have to be on your foot and make sure that everything’s proportion is just right.

But a blunder can occur and you’ll have to take action to fix them. An example of such a mess would be seeing black spots on oregano leaves.

However, you don’t have to worry. When there is a problem there is always a solution. So, let’s take a look at these reasons causing this problem along with the solutions.

Reason 1: Caterpillar Residue on Oregano Leaves

You see, at times you might misinterpret a caterpillar’s feces as black spots. In fact, many people make this mistake on a regular basis.

They get freaked out about the black dots and start imagining the worst possible scenario. Like their plant was invaded by some deadly fungi or bacteria. And it might never heal.

So, before you give yourself a jump scare it’s best to check if the black spots are caterpillar residue or not. 

And once you’re sure it’s just the caterpillar using your leaves as a washroom you can take measures to fix them.

Solution: How to Remove Caterpillar Residue from Oregano Leaves?

Once you assure yourself that the black spot is nothing more than caterpillar residue you can wash it away. Now, don’t worry; you won’t have to get your hands dirty for this.

All you need is a water hose at high pressure. That’ll spray the feces away. However, you need to be a bit careful about the pressure of the water hose.

You see, spraying the plants with too much water can prove to be quite detrimental. So, you have to make sure that the pressure isn’t set to max.

And even after that if the residue doesn’t leave you to need to get up close. For that, you need a spray gun. Then use it to spray water at high pressure on individual leaves.

That’ll do the trick.

Reason 2: Fungi Attack

One of the many reasons for the black spots on oregano leaves is a fungi attack. You see, your plant leaves turning brown or black might indicate that little pest are make themselves home in the moist soil of yours.

And as you need to keep the soil moist for the oregano this gives the fungi a great opportunity to grow. Plus, due to lack of air circulation, the fungi can thrive in your garden quite well.

So, you can’t count on them to leave your garden any time soon. Instead, you need to do something about it. Want to know how to take care of the fungi?

Then keep on reading. The answer is just up ahead.

Solution: How to Deal with Fungi on Oregano Leaves?

The fungi can be quite annoying. Since they won’t go away on their own you need to force them to leave. To do this you have to prune the plant.

Now, opening them up will allow more air circulation. And the fungi hate them. They can’t bear it and die out in a matter of days.

However, if you don’t want to prune your beloved plant you can always fix the drainage system. Since the fungi can only survive in a moist place, then make a moist free environment.

For this, you need to upgrade your drainage system. So, that water doesn’t stay around to promote the growth of fungi.

Reason 3: Pest Problems

Keeping your plants safe from pests are the toughest experience. Yellowing leaves, brown leaves and black dots on your plant leaves are signs that your plant is affected by their existence. You see, pests like Aphids and spider mites are always crawling around the garden.

And their favorite snack is the oregano leaves. So, while having their lunch they aid in turning the leaves black.

In addition to eating your oregano leaves these pests also damage the entire plant. That’s why it’s crucial to scoot them away before they completely damage the plant.

Luckily for you, the damage control is not that hard. Even a beginner can do it. So why don’t we take a look at the solution?

Solution: How to Keep the Pest Away?

The easiest way to keep the pests off your plant is to spray the plants with a water hose. All you have to do is adjust the pressure of the water hose and then spray.

Now for the pressure, you need to make sure it’s not too much or too little. Because too much pressure will damage the plants and too little won’t throw off the pests.

Do this regularly and you’ll see some amazing results. But in case you don’t see the pests flying away then use insecticidal soap or neem spray.

They’ll get rid of the pests from the root and your oregano leaves will be able to grow happily.

In Conclusion

Well, that marks the end of our article on black spots on oregano leaves. We hope you got the answer you were looking for.

But if you still have further queries don’t hesitate to leave a comment. We are here to help.

So, that’ll be all for now. Hope you have a good day. Take care. Bye-bye!

As an Amazon Associate I earn from qualifying purchases.

Celina Nance

It’s been a life-long wish of Celina Nance to have a lawn full of colorful flower beds. But living in Arizona city, that seems kind of impossible. But Celina Nance didn’t stop and created a full-form balcony garden instead. And he often shares stuff that he does/solves/innovates throughout the journey.

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