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I Lost My Prized Oregano Plants to Nasty Pests So Now I Protect Them with These 6 Methods

Small potted oregano plant in a terracotta pot on the porch

Introducing Oregano, the Pests that Hurt Them and How to Protect Them From Pest-Ridden Harm

Where would we be without oregano? Pizza sauce would be bland, stews would be colorless, gardens would be down a solider, and folks would be desperate for a natural cough and cold remedy.

There are so many reasons to plant this essential culinary herb in your garden, but much like other garden herbs, oregano can experience some issues that may deter you from ever trying to grow oregano again. 

Though oregano is definitely more tough than say basil or sage, it still has its battles to fight. This article is going to go through some pests and diseases that oregano could face in your garden or on your windowsill, and exactly how to squander them!

How to Deal with Oregano Issues 

Beautiful fresh green leaves of the oregano plant


Origanum vulgare – the most common species of oregano – is one of the easier herbs to grow as long as it’s in the right place. The easiest way to prevent pests and disease from overtaking your plant is ensuring that it’s planted in the perfect spot. 

Oregano grows best when it’s in an area that receives direct sunlight for most of the day, it should be planted in well draining soil, and the most important part is that each plant has enough space from the others to ensure good air circulation through its leaves. Oregano also shouldn’t be watered too frequently, let the soil dry out between waterings. 

Proper spacing is essential, but pruning is also a great way to prevent the following issues from occurring. Pruning length or bushy branches that are squashing the herb will allow for more spread out growth, removing the potential for clogging leaves.

Fungal Diseases 

Diseases that affect oregano are almost always different types of fungi. Fungi thrives in moist conditions where there isn’t great air circulation – hence why it’s so important to give your oregano plants tons of room to breathe. 

This is also why it’s important not to over water your oregano herbs. If the soil and leaves aren’t given a chance to dry out completely, they will be way more susceptible to infestations from disease and pests. There are 3 main diseases that affect oregano: 

  1. Botrytis Rot – this fungal disease will cause your oregano plant to rot. The easiest way to tell if your oregano patch has developed botrytis rot is if the roots and/or leaves start to rot. 
    : unfortunately, there is no cure for this fungal disease. The only way that you can deal with this is by removing and destroying the infected plants. 
  2. Rhizoctonia Rot – you will be able to tell that your plant has developed rhizoctonia rot if your oregano plant starts to show gradual signs of wilting starting from the roots. If the base of the stems are turning brown, you’ve got rhizoctonia rot.Cure: this is another disease that has no cure. Since it develops in wet soil, you’ll have to remove and destroy the infected plants, and avoid planting anything in that area for minimum 3 years.
  3. Rust – Ruse is another fungal disease, but this one is the most common and the least serious. You will be able to tell that your oregano plant has developed rust in you spot small circular brown spots on the foliage.Cure: if you manage to catch the rust early enough, you can simple prune the infected branches away before it spreads to the rest of the plant. Make sure to properly dispose of those infected branches.

Beautiful growing oregano plant in the sunlight


If you didn’t already know, oregano is itself a natural insect repellent. Gardeners will often plant oregano alongside plants that are very susceptible to pest infestations to help ward them off. 

Though oregano is an incredible companion plant (otherwise known as symbiotic gardening) for plants like tomatoes and strawberries, they are not to completely immune, and are still affected by this handful of pesky little pests: 

  1. Aphids – aphids are one of the most obvious pests to spot, and chances are if you’re a plant lover, you’ve been bothered by them before. Aphids are sap sucking insects that will stick close to veins of plants and look like tiny little black grains of rice. Cure: you can get control of mild infestations with a good strong hose to try to know them off. You can also pick them off by hand, or use a cloth that is doused with insecticidal soap – though this may be tricky since oregano leaves can be so small. 
  2. Spider Mites – these are tiny little bugs that stick close to the stems of plants. You can tell you’ve got spider mites if there are tiny spider-web like wisps around the base of the oregano branches. Cure: spider mites are pleasantly easy to deal with, since they don’t cling so hard to leaves as aphids do. A gentle spray of water should be rid of them, or you can spray your plant with insecticidal soap (I like using a Dr.Bronners solution since it’s all natural). 
  3. Leaf Miners – leaf miners are the larvae of black flies. They look like tiny little worms and they like to feed on the inside of oregano leaves. You can tell you’ve been infected with leaf miners if you notice little brown trails all over your oregano leaves. Cure: since these suckers hang out inside leaves you won’t be able to spray them off. You’ll simply have to pick away all the leaves that have trails on them and properly dispose of them before they larvae mature into adults. 

How do you Dispose of Infected Oregano Plants?

Focus image on growing rosettes of oregano leaves

If you’ve been so unfortunate to have to deal with any of the above mentioned issues, chances are that you’ve had to prune away a significant portion of your plant, or you need to dispose of it entirely. 

This isn’t so simply as tossing it in the trash, as infected specimens need to be discarded in a responsible way. Many people think that you can just toss an infected plant in the compost – it’s all natural after all – but this could be detrimental. 

If you add an infected plant to your compost bin, you pose a very strong chance of infecting your entire garden with the same pest or disease. Many of these funguses and pests can survive, if not thrive, in the temperature of a compost bin. If you are planning on incorporating your compost in your potting soil, you’re basically saying goodbye to your entire garden. 

The most responsible way to be rid of infected plants is by burning the plants (then you can compost the ashes) or you can place the infected plants in a sealed plastic bag and then dispose of them in the garbage. 

Lovely green leaves of a growing oregano plant