Common Watermelon Peperomia Pests and Diseases

One minute you have a vibrant peperomia plant (Peperomia argyreia) covered with beautiful green leaves. And the next minute, it’s covered with crawling pests or alarming diseases. Don’t worry! I’ll cover some of the most common pests and diseases and explain how to deal with them.

Common Watermelon Peperomia Pests and Diseases

Key Takeaways

Common Watermelon peperomia pests include sap-sucking critters such as aphids, spider mites, and scale. You can remove these insects with a soapy rag or spray them with neem oil or insecticidal soap. The most common diseases are root rot and peperomia ring spot.

How to Prevent Pests and Diseases

The number one way pests enter the home is by introducing infected plants. Bringing a new plant home is great! But check it over before you place it with other plants.

I like to spend a few minutes examining the plants’ leaves and looking for hidden critters. Since aphids, spider mites, thrips, and gnats are small, they often go undetected. If I notice any of these pests on the plant, I remove them and keep the plant in a separate room. Once the plant is free from pests, it’s ready to hang out with the rest of my plants.

Diseases can enter your home on other plants, but they can also enter your home via infected potting soil or pots. Make sure only to use potting mix from trusted sources, and always sanitize old containers before reusing them.

Watermelon Peperomia Pests

Watermelon peperomia plants are susceptible to many of the same pests that affect other houseplants. Watch out for the following critters and remove them ASAP.



Aphids are a large group of tiny, sap-sucking pests. Although they’re small in size, they can quickly multiply and cause serious damage. Larger populations cause severe leaf stippling and yellowing leaves.

All aphids remain smaller than 1/8 of an inch. The pests come in various colors, including green, brown, yellow, and red. Identifying the specific aphid species is unimportant since you can treat all aphids the same.

If you notice a few aphids on your plants, you can easily wipe them off using a wet, soapy rag. You can also use this method for larger infestations, but it may not work if your whole plant is covered. When that’s the case, spray the aphids with neem oil or insecticidal soap. Since these products work on contact, make sure to thoroughly coat all of the pests.

Spider Mites

Spider Mites

Spider mites are another class of small, sap-sucking pests that attack watermelon peperomia plants. These arachnids pierce holes in the plant’s leaves, causing many small dots. You may also notice they form a spider-like web. 

They’re more likely to occur at low humidity levels, so keeping the humidity at a moderate to high range can keep them away.

If you notice spider mites, remove them with a soapy rag or a forceful spray of water. Other treatment options include spraying the spider mites with insecticidal soap or neem oil.

Fungus Gnats

Fungus Gnats

These pesky critters generally don’t damage watermelon peperomia plants, but they’re a general nuisance to deal with. If you see a cloud of small insects flying around your houseplant, you’re likely dealing with fungus gnats. These pests typically appear when potting soil remains moist.

Although they typically don’t harm plants, their larvae can feed on roots.

Yellow sticky cards are one of the best ways to control fungus gnats. The pests flock to the yellow color and get trapped on the sticky surface. At this point, you can throw the card away.

Watermelon Peperomia Diseases

Fortunately, watermelon peperomia don’t experience many diseases. However, you should keep an eye out for the following.

Root Rot

If you have houseplants at home, you’ve probably heard of root rot. People use this term to refer to various fungal diseases that impact plant roots. Some specific types of root rot include Phytophthora, Pythium, and Fusarium.

Most types of root rot are more likely to occur when the soil is wet. Therefore, it often occurs when you overwater your watermelon peperomia plants.

The first signs of root rot often look like the plant is underwatered. The leaves become droopy, wilted, and possibly discolored. That’s because the plant’s roots cannot properly take up water. If you remove the plant from its pot and inspect its roots, you’ll notice soft and/or discolored roots.

If you suspect your plant has root rot, decrease the amount you water it. Remember, watermelon peperomia plants only need water when their leaves lose rigidity. You can also rim off infected roots and repot in fresh potting soil.

For more, see our in-depth guide to watering watermelon peperomia plants at home. 

Peperomia Ring Spot

As the name suggests, this disease attacks peperomia plants, such as the watermelon peperomia. It causes concentric rings on the leaves. Unfortunately, there’s no cure for this disease, so you should discard any infected plants.

Wrapping Up

By keeping an eye out for these pests and diseases, you can keep your watermelon peperomia plant healthy.

Contributing Editor | | Full Bio

Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.

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