Why Are There Holes In Coleus Leaves? (3 Reasons & Treatments)

Coleus plants are resistant to most of the common diseases caused by pests and insects.

But many beginners and experienced houseplant owners have seen irregular random holes here and there in their coleus leaves. If you are wondering what those holes are, then this article is for you.

Keep reading to learn what makes those holes in coleus leaves and what you can do to prevent them in the future.

Why Are There Holes In Coleus Leaves?

Pests and bugs eating the leaves is the main cause of holes in coleus leaves. Slugs, snails, caterpillars, cutworms, etc are among the bugs that coleus plants frequently encounter. Along with these pests and insects, holes in coleus leaves can also be caused by bacterial and fungal infections, improper handling and care, etc.

Let’s discuss the three causes of holes in detail with signs, recommended treatment methods, and possible preventive measures.

1. Pests eating coleus leaves

If you are seeing holes in your coleus leaves, pests eating the leaves must be the real cause 99% of the time.

Coleus plants are considered to be one of the favorites of snails and slugs. It is not a surprise, because coleus has very soft leaves which are very easy for the pests to eat and digest.

The commonly seen pests around coleus plants include,

• Snails
• Slugs
• Caterpillars
• Cutworms
• Beetles & flies
• Aphids, mealybugs & spider mites

These pests attack coleus plants based on the location of the plant. If the plant is kept indoors, small insects like aphids, mealybugs, spider mites, and flies cause the damage. On the other hand, if your coleus is kept outdoors, then snails, slugs, caterpillars, etc can grab a bite.

Signs of pests – 

By personally inspecting your coleus plant with a magnifying glass or lens, you can determine whether it is infected with pests.

Different pests and insects leave different types of markings and impacts on the leaves. For example, slugs and snails create large irregular shaped holes whereas cutworms start with a small dot-like hole.

It is also recommended that you inspect the plant during nighttime also with the help of a flashlight. Some of the leaf-mining insects like liriyomyza melanogaster are only active at nighttime and they will hide under the soil during the daytime.

Treatment Methods – 

If you find pests and bugs in your coleus plant, then you should remove them on priority. 

Some of the pests like aphids and spider mites reproduce very quickly and in no time, the entire plant will be colonized. Also, most of these pests can easily travel and affect nearby plants, if you have any.

Different pests need types and concentrations of pesticides. But as a starting point, you can use insecticidal soap solution, neem oil, or diluted peppermint oil to clean the leaves and stem affected.

If the infection is very severe, then you should look for pest-specific pesticides because they are advanced chemical formations specifically made to repel them.

Preventive Measures – 

If preventing pests is easy, then everyone would’ve done that right?

The only practical way to prevent pests from eating the leaves on your coleus plant is to keep them away from your plant. 

You should strictly adhere to a few rules, such as routinely checking the plant and its nearby areas for pests and maintaining a clean and organized environment around it.

2. Bacterial & fungal diseases

Bacterial leaf spot is a commonly seen plant disease among ornamental plants in the US.

Other than bacterial leaf spot disease, a couple of fungi like downy mildew, Cercospora Cassicola, etc also triggers problems for coleus plants.

Initially, these bacteria and fungi will not create holes. The leaves turn yellow and then brown as the infestation progresses. Once the infected leaves start maturing, the brown areas will eventually evolve into holes.

Signs of infection – The leaves have a few brown or yellow patches or spots here and there.

Treatment Methods – 

If the infection is in starting stage, then you can try and use natural or chemical fungicides like baking soda powder. 

But, if the infection is severe, then the best you can do is to isolate the plant and repot the entire plant in fresh potting soil and container after thoroughly cleaning the plant with chemical fungicides.

Preventive Measures – 

Most often, the water you provide to your plant is what causes bacterial and other fungal diseases of a similar nature. Always use UV-treated or sedimented water to minimize the risk.

You must watch out when watering to avoid getting the leaves wet in order to avoid these diseases.

3. Improper handling & care

If you are hundred percent sure that there are no pests or bacterial infections in your coleus plants, then holes might be due to improper handling and care.

Till now, we were blaming the pests and insects. Now, it’s time to take the blame yourselves, since handling and care is your responsibility as a plant owner.

Coleus leaves are very soft and they are easily damaged even by a strong wind. So, always ensure that you are not keeping the plant in a spot where the wind is harsh.

Also, move the plant from one spot to another only if necessary.

Mistakes in the care routine can also cause holes in coleus leaves sometimes. For example, too much fertilizer or light can cause leaf burn which might sometimes turn into holes looking similar to bacterial spots.

Holes In Coleus Leaves – Frequently Asked Questions (FAQs)

Let’s take a look at some of the commonly asked questions on the forums and exchanges related to holes in coleus leaves.

Wrapping Up

Small holes are a common sight in the coleus plant leaves. And, if you are someone who gets annoyed seeing them, then it’s time to come back to normal.

Sit back and relax. Take out a magnifying glass and inspect the sides and undersides of the damaged leaves. If you find the culprits hiding, then use scientifically proven treatment methods to clear them up.

Also, watch out for the pests periodically so that you can catch them before damage next time.

After all, dealing with pests is also a part of the gardening routine that you are passionate about right?.

Sources

To back up the information we provide in our articles, the Plantials team only uses high-quality sources published in peer-reviewed university or scientific research journals.

1. The first introduction of Xyleborus affinis (Coleoptera: Scolytidae), Folia Entomologica Hungarica Via Researchgate.
2. Liriyomyza Melanogaster Profile, University Of Florida.
3. Plant Pests, University Of Florida.
4. What’s Eating My Plants, University of Massachusetts Amherst.