Few types of peperomia are better known than the watermelon peperomia. If you want to grow the peperomia with the watermelon stripes or propagate one to easily multiply the amount you care for, I’ll tell you everything you need to know in this extensive watermelon peperomia guide.
I’ll begin by covering the best watermelon peperomia care and tips before explaining in detail how to propagate and finally go over the most common peperomia watermelon pests, diseases, and more.
Let’s get started.
Table of Contents
- Watermelon Peperomia Care and Propagation Overview
- Watermelon Peperomia Care
- How to Propagate a Watermelon Peperomia
- Common Issues with Watermelon Peperomia
- Watermelon Peperomia Common Questions
Watermelon Peperomia Care and Propagation Overview
What is the watermelon peperomia and what makes it different from other peperomia species?
The technical name for the watermelon peperomia is the Peperomia argyreia. This indoor plant species grows natively across the northern parts of South America, such as Venezuela, Ecuador, Brazil, and Bolivia.
Sometimes, you may hear of the watermelon peperomia being referred to as the watermelon begonia. The watermelon peperomia plant is not a begonia.
So why the watermelon part of its name? The Peperomia argyreia has nothing to do with the watermelon plant itself except for its similar coloration.
You know how the outside of a watermelon is light green with darker green stripes, right? The watermelon peperomia mimics that coloration across its large, wide leaves.
You might see some silvery sheen to the watermelon peperomia’s foliage. This is where the argyreia part of its name comes from. Argyreia is a Latin term that means “silvery.”
The watermelon peperomia in maturity reaches sizes of nearly eight inches wide and tall. It’s not a large plant, but it is bigger than some types of peperomia.
Watermelon Peperomia Care
Enjoying those trademark watermelon stripes of the Peperomia argyreia is not a given. You must provide the right care for your watermelon peperomia plant.
This section will be your guide, as I have plenty of information that will help you master the watermelon peperomia’s care!
Watering a Watermelon Peperomia
The watermelon peperomia is a semi-succulent. What this means for you is that you’ll water it more seldomly than your non-succulent plants yet more often than true succulent species.
Allow several inches of the watermelon peperomia’s soil to dry out. If the soil feels dry about two or three inches deep, then enough time has elapsed.
When you do provide water to the plant, you want to be generous about the amount you give. That goes double if you live in a warm climate. Otherwise, water with gusto during warm seasons, then scale back during the winter.
I really must stress how important it is to balance the watermelon peperomia’s water requirements just right.
Some plants just wilt or get a little crispy if you’ve neglected to water them for too long. The watermelon peperomia might have a more dramatic reaction, so don’t let conditions ever reach bone-dry status.
Overwatering is one of the fastest ways to accelerate the plant disease known as root rot. You cannot have standing water in the watermelon peperomia’s pot, nor can you saturate the soil past a soggy state.
If you’re not sure how moist the watermelon peperomia’s soil is, use the fingertip test. It won’t fail you.
Watermelon Peperomia Light Requirements
Indirect light is frequently recommended for peperomias, and that’s true of the watermelon peperomia as well.
You might opt for bright, indirect light from a northerly or easterly-facing window with a curtain. This sunlight is never scorching, so it shouldn’t burn the leaves of your watermelon peperomia.
Instead, you’re nourishing it with enough sunlight to properly photosynthesize and thrive indoors.
I know that some indoor gardeners say that medium indirect light is more suitable for their watermelon peperomias. I also think placing your watermelon peperomia closer to a window that’s only providing medium indirect light can work.
Where my thinking differs is instead of having to place my indoor plants so close to the window to get their ideal light, I prefer to keep plenty of space between my indoor plants and the window that’s providing their ideal light for photosynthesis.
This way you have leeway to move your watermelon peperomia / indoor plants closer or further away from the window and accommodate long periods of sunlight, rainy weather or even seasonality.
If you’re not familiar with the expression or terms “Medium indirect light” let me explain:
Medium indirect light is even dimmer than bright, indirect light. The sunlight might reflect off a surface and then hit your plant, or perhaps tree leaves overhead prevent direct sun rays from getting through. Even a window shade can provide medium indirect light.
The latter type of light does better replicate the natural growing conditions of the watermelon peperomia. In the wild, this plant would be under the shelter of bigger trees and plants.
Besides receiving indirect medium sun, the watermelon peperomia would also get periods of shade as well.
That said, I caution you against giving this plant too much shade.
The watermelon peperomia is a variegated indoor plant species. Variegation refers to the unique coloring and patterns that some plants have.
Best Soil for a Watermelon Peperomia
Well-draining potting soil is a must for the watermelon peperomia. If you can, select a rich potting soil or mix full of soil amendments.
Which soil amendments are suitable for this peperomia variety?
You can add one part perlite and one part peat moss to the watermelon peperomia’s pot.
The small chunks of white rock that are perlite will aerate the soil and encourage healthy drainage. Perlite can retain water, but not past a reasonable degree.
Sphagnum moss aka peat moss aerates the soil and retains moisture so your watermelon peperomia doesn’t dry out too quickly. Once you begin fertilizing, peat moss is known for its nutrient retention as well.
Oh, I should note that despite the watermelon peperomia’s status as a semi-succulent, you should never use succulent potting mix for a watermelon peperomia.
A succulent mix is going to be way too dry, preventing the watermelon peperomia from absorbing enough water. Even if you’re properly watering your peperomia it will think it’s being underwatered due to the lack of water retention that happens in succulent soil mixes.
What does an underwatered peperomia plant look like?
An underwatered watermelon peperomia plant will exhibit signs of stress such as wilting, leaf curling, and foliage discoloration.
Best Type of Pot to use for a Watermelon Peperomia
Selecting the right type of pot for the watermelon peperomia can be challenging since its soil can’t get too dry nor too soggy.
Unglazed, these are the most porous pot materials around. Clay, terracotta, and the like ensure there’s not one drop of water extra than what should be in the soil.
However, that could lead to very dry conditions for the watermelon peperomia, which is a no-no.
A glazed ceramic, clay, or terracotta pot is semi-porous.
In other words, the pot can still absorb excess water, but not to the same degree as before. This will maintain some soil moisture to prevent your watermelon peperomia from drying out.
When shopping for a pot for your peperomia plant, always ensure it has drainage holes.
I also want to talk about sizing the pot for your plant. I recommend measuring its current diameter and then buying a pot that’s an inch or two bigger than that.
I only say this because the watermelon peperomia is likely to become rootbound. That means its roots can grow circularly around the pot, making it almost impossible to pull the plant out and exchange its pot later down the line.
Watermelon Peperomia’s Ideal Temperature and Humidity
The watermelon peperomia doesn’t need special temperatures. If you keep temperature around your peperomia between 65 and 80 degrees Fahrenheit, this plant will be happy.
Considering that 65 degrees to the mid-70s is room temperature anyway, there should be no need to adjust your thermostat. Even in the winter and the summer, temps should stay within this range.
With its native home a warm and balmy place, the watermelon peperomia doesn’t have a ton of tolerance for very cold temperatures. By night, temps should drop no lower than 60 degrees.
Once the mercury hits the 50s, you’re going to see your watermelon peperomia go into cold shock.
Its growth will stop, and its leaves could wilt or shed. In a worst-case scenario, the plant’s cells could even freeze and die in areas.
You’d then have to prune the dead leaves and carefully monitor your plant over the next several weeks.
If the temperatures are pushing close to 80 degrees, the watermelon peperomia will be fine.
After all, the peperomia is nicknamed the radiator plant for a reason.
That said, every plant has its limits. You don’t want to be in a home or office that’s close to the mid-to-high 80s, so don’t put your plant through that as well.
Speaking of warmth, I have to talk about the humidity requirements for the watermelon peperomia. Well, they’re not really requirements, per se, as average relative humidity suits the watermelon peperomia just fine.
Let me explain average relative humidity for a moment.
Humidity is in the air indoors even if you don’t feel it. Most homes and offices have an average relative humidity of up to 50 percent, and this amount of humidity is especially suitable for the watermelon peperomia.
Best Fertilizer for a Watermelon Peperomia
To support your watermelon peperomia, feed it fertilizer from the spring until the end of summer (the plant’s active growing season). You can use water-soluble plant fertilizer or liquid fertilizer, that’s up to you.
No matter which product you choose, it should contain a balanced mix of macronutrients nitrogen, phosphorus, and potassium.
You also must dilute the fertilizer strength to at least half when it comes to fertilizing your watermelon peperomia.
Moisten the soil before applying fertilizer. Reapply at least monthly. If your watermelon peperomia seems a little sluggish in the growth department, you can try fertilizing it once every two weeks.
Just watch out for fertilizer burn, which can occur if you’re overdoing it on the fertilizer.
Your plant will begin to wither, and its leaves will become brown or black. The soil may also have visible fertilizer residue.
If your watermelon peperomia is suffering from a case of fertilizer burn, you should discontinue fertilizer use immediately. You might also want to move the plant to a pot with fresh soil.
How to Propagate a Watermelon Peperomia
One of the best parts about growing indoor plants is that you can share them with the other people in your life. Not just by giving your only plant away but through propagating your plant to make more of the same plant.
By propagating your plants you’re able to keep your plant and give copies or clones of your plant to people you love and want to share your plants with.
When it comes to propagating the watermelon peperomia, propagation can be done successfully through “cuttings”. Propagation entails taking a plant cutting and growing a new plant from it. Here’s how it’s done.
Select a Cutting
What’s cool about propagating a watermelon peperomia is that no leaf node is required.
A leaf node is where the next plant growth will occur. You can usually find it on the stem since it’s a swollen, bulbous area.
Besides stems, you can also take a peperomia leaf and grow a plant from there.
Select a healthy leaf and trim perpendicularly from the direction of the stripes.
Prepare the Growth Medium
In the case of a stem cutting, you can propagate a watermelon peperomia in a cup of water. For leaf cuttings though, you’ll need soil instead.
When choosing a cup or container to fill with water, it should be deep enough that when full, the stem cutting’s petiole is in the water, but any attached leaves are not.
If you’ve chosen soil as the growing medium, you can use standard potting soil. Keep the soil moist but never soaking.
Here’s a trick that will keep conditions humid for your growing watermelon peperomia cutting. Take a large plastic zippy bag, open it up, and carefully insert it over your plant.
Inside the bag, conditions will become quite humid. Just give your plant time to air out for a while every few days!
Let the Roots Develop
It will take several weeks for visible roots to appear. Once this happens and you feel the roots are strong enough, you can take a cutting planted in water and transfer it to a pot with soil.
If you already selected soil as your growing medium, then there’s no need to move your cutting.
Common Issues with Watermelon Peperomia
Is your watermelon peperomia not quite growing to its full potential? Getting to the root cause is the only way to ameliorate the issue so your plant can become full, healthy, and beautiful.
Let’s examine the pests and diseases that can impede your watermelon peperomia’s progress.
Most peperomia species aren’t particularly prone to insects, and that’s true of the watermelon peperomia as well. A healthy plant especially shouldn’t have any bug problems, but a weak one can easily become susceptible to a swarm.
Here are some insect species to swat off when you see them.
When spider mites gather in big numbers, they suck up plant juices and weave tiny silk webs.
All this activity happens underneath your watermelon peperomia’s leaves, so make sure you inspect those regularly.
If you find spider mites when you look, you can use common household products such as rubbing alcohol or dish soap to kill the insects. Mix with water and apply on a cotton ball, rubbing the underside of the leaves.
Whiteflies might not cause any trouble to us people, but they will ruin your indoor (and outdoor) garden. These tiny, winged insects also will camp out underneath the leaves of your watermelon peperomia.
It’s again dish soap to the rescue. Mix a tablespoon of the stuff with a gallon of water, put it in a spray bottle, and mist until the whiteflies are gone.
Have you noticed white, cotton-like growths on (you guessed it) the underside of your watermelon peperomia’s leaves? That is indeed a mealybug infestation.
My favorite way to ensure the mealybugs are gone is to combine dish soap and rubbing alcohol with water in a spray bottle.
Like most indoor plants, peperomias can fall victim to viral, bacterial, and fungal diseases.
This overview of the four most common watermelon peperomia diseases will tell you what to look out for and how (if possible) to cure the disease.
Root rot is caused by overwatering your plant or poor drainage, as is the case with most fungal diseases. The standing water remains in the pot, preventing the roots from receiving enough oxygen.
One by one, the affected roots begin to die. Since roots sustain the growth and health of your entire plant, it’s not too much longer before your watermelon peperomia will decay.
The plant will exhibit leaf discoloration, wilting, and slowed growth.
Without intervention, the entire plant will die. Sometimes, even if you do try to fix the plant by cutting away dead roots, the plant still dies because its root system isn’t healthy enough to sustain it.
Overwatering can also contribute to oedema, a disease that occurs when a plant has more water in its leaves than it knows what to do with.
The leaves usually receive water from the roots and then release it out of their pores in a process called transpiration.
When an indoor plant develops oedema, the water remains in the leaves’ veins and can cause the cells there to explode.
The resulting patches look wet at first, then they dry and almost resemble cork.
The best treatment for plant oedema is prevention.
The Mycosphaerella brassicicola fungus causes ring spots in indoor plants like the watermelon peperomia.
The high humidity the plant requires also can cause unsightly brownish marks to appear across the watermelon-striped foliage. Once this happens, you have no choice but to remove the affected leaves and amend care habits in the future.
Watermelon Peperomia Common Questions
Do you still have a question or two on your mind pertaining to the watermelon peperomia? I have the info right here!
Do Peperomia Need to Be Misted?
While misting a plant with a spray bottle can slightly increase its humidity, peperomia Do not need to be misted.
The issue with misting though is that you have to spend quite a long time sitting (or standing) there squeezing the spray bottle handle over and over.
It’s torture! You have things to do besides sit around and mist your plant all day.
As you’ll recall, the peperomia plant only requires average relative humidity anyway. Misting this plant would just be a waste of your time.
Is the Watermelon Peperomia Toxic to Pets?
The peperomia plant is non-toxic to both cats and dogs.
That said, some pets are more adventurous or curious then others and might want to chew on or even ingest your plants. It’s always wise to place your plants somewhere that deters your pet from having easy access to any plant you’re growing. Too much of anything, (even non toxic plants) can be a bad thing.