Watermelon Peperomia (Peperomia Argyreia) is a South American plant that’s grown for its attractively striped leaves which look just like a ripe watermelon, which is how it gets its name.
These are small but striking plants, typically reaching 12 inches in height with dwarf varieties only reaching 6 inches tall. They grow well outdoors providing the climate suits them, but can be grown easily indoors wherever you live.
Their main showpieces are their lush, waxy leaves, but they do also produce small green flower spikes.
They’re a great plant for beginners or for anyone who wants a low-maintenance plant, as they aren’t fussy and will grow easily as long as they get enough light, are kept out of very cold weather and aren’t overwatered.
They grow well in pots as well as hanging baskets, and they’re also non-toxic to pets, which is great if you have furry family members.
How to Grow Watermelon Peperomia
The ideal conditions for growing watermelon peperomia include:
- Temperature - Peperomia Argyreia are fairly tropical plants, so they like temperatures between 50-80 degrees Fahrenheit and it’s recommended as an outdoor plant only in hardiness zones 10 through 12.
If you are planting it outdoors where temperatures will be out of these zones, it’s best to plant it in a pot that you can move indoors in icy weather or keep in the shade during the hottest months.
It will not tolerate frost at all and will drop its leaves as soon as it gets too cold..
- Light - Place your plant a bright space where it doesn’t get direct sunlight. They naturally grow close to the ground in thickly shaded undergrowth, so out of direct sunshine in a West, East or South-facing room is perfect.
If you are planting it outside, you want it to be sheltered from direct sun, underneath trees or a patio roof. If you notice the dark lines in the leaves are becoming less prominent, your plant is getting too much light.
Once you move it into a less-bright space, the color will revive.
- Soil - These plants like moisture without being waterlogged, so use a soil that is low in clay and drains well. The best is a peat-based soil which is two parts peat to one part perlite.
You can find this easily at your local garden center if your yard’s soil has too much clay.
- Watering - Overwatering is the most common reason for a watermelon peperomia to die, so be careful with this. Make sure to use the right watering can so avoid this.
Only water when the top one-inch of soil is dry, and then water it thoroughly, letting the excess drain away and ensuring the plant’s roots are not sitting in water.
If the weather is very hot or the leaves start to droop and the soil is dry, you should water slightly more frequently.
In the fall and winter, you can water less frequently, only when that top layer of soil is dry.
- Fertilizer - As a low-maintenance plant, it won’t need much fertilizer if planted out in your yard, and will thrive on any 10-10-10 all-purpose fertilizer or mulch you apply in spring and summer.
Indoor and potted plants need a bit more in the way of nutrients, and we recommend a liquid or granular all-purpose fertilizer every 2-4 weeks through spring and summer.
It’s easy to over-fertilize and kill a potted plant, so use the fertilizer at 1/2 to 1/3 the manufacturer’s recommended strength.
Overfertilizing can also cause the plant to grow spindly and leggy rather than thick and bushy.
Avoid Overwatering Your Plants
Overwatering is the most common problem people experience with these plants, as it’s pretty easy to do!
Signs of overwatering include wilting and raised protrusions on the leaves that look a bit like scabs.
If you notice these, stop watering immediately and leave the soil to dry. If the soil is very waterlogged, repot the plant in dry peat and perlite mix and water less frequently.
Overwatering can kill your plant, so it’s important to notice these signs quickly and correct your watering schedule so that you only water when the top inch of soil is dry.
Misting Your Peperomia
Since your Peperomia Argyreia is a tropical plant, it does love humidity. You can add this by softly misting the leaves (not the roots or soil) every day, especially in dry weather or when indoors during winter, as heating often dries out the air.
It will also enjoy being in a room when you’re using a humidifier. You can place it on a humidity tray, which is a tray of pebbles in water.
The plant container must rest on top of the pebbles, not in the water, and it will benefit from the humidity that occurs as the water evaporates.
Repotting Watermelon Peperomia
Although it is a slow-grower, over the years your plant will need to be re-potted as it outgrows its pot or depletes the soil content.
You will notice your plant needs repotting if you have had it for a few years and starts looking rootbound, with roots pushing up out of the soil and not a lot of soil left in the pot.
When repotting watermelon peperomia, choose a slightly bigger pot than the current one. These plants like a tight fit, so only go one or two inches bigger.
Make sure the pot has at least one drainage hole. Use a mix of two parts peat to one part perlite and fill the pot part of the way.
Fit your peperomia into the pot and fill until the roots are well-covered, and the plant is stable without covering the stems.
Water it thoroughly, but don’t let the plant sit in water.
Propagating Watermelon Peperomias
Peperomia Argyreia plants are wonderfully easy to propagate, and you can turn one plant into dozens by growing them from existing leaves and stems! Here’s how.
- From leaf cuttings – This is the easiest way to propagate these plants. Cut a leaf in half from stem to tip and gently press it into a mix of two parts peat to one part perlite.
The new roots will start appearing from the leaf veins within a week or so, with new stems and leaves appearing in the weeks after.
You can speed this process up with the best rooting hormones in the market.
- From stem cuttings – Cut a stem with a leaf and place the stem in clean water where it gets indirect light.
Replace the water every few days. Once roots appear from the stem, you can plant the stem in the peat and perlite mix. Be careful while you do this, as the new roots are very delicate.
Your propagated plants make beautiful gifts too!
Protecting Your Plant from Diseases and Pests
Luckily, these plants have very few issues with diseases and pests.
As long as you keep them healthy, fed and watered with enough light, they’ll be strong enough to ward off most common issues.
However, if your plant is overwatered, it can develop root rot. The roots turn brown and mushy, and the leaves will wilt and die.
This can kill your plant, so it’s best to take a few healthy leaves and propagate a new plant, or remove the dead roots and repot your plant in dry, well-draining soil.
If your plant is weak due to overwatering, not enough fertilizer or too little light, it can also become vulnerable to common pest infestations like mealybug, spider mite and whitefly.
You should then isolate your plant from other houseplants, correct its climate, manually remove the insects where you can and spray with an insecticide or neem oil regularly for a few weeks to ensure you kill eggs as well as adult pests.
If you notice tiny black flies hopping and crawling about on your soil after you have repotted your Peperomia Argyreia, you may have an infestation of fungus gnats.
They are a harmless nuisance and commonly arrive in potting mix or from other affected plants in the same store. You should treat this with an insecticide or neem oil as soon as possible, as they will spread to other plants.
Now You Have What It Takes for Your Watermelon Peperomia to Thrive!
Peperomia Argyreia is a striking tropical plant that creates an elegant focal point in any home or tropical backyard, bringing an element of the South American jungle into your space.
They’re easy to maintain when you remember to water them thoroughly but infrequently, keeping the roots from sitting in water and the leaves out of direct sunlight.
With light feeding in spring and summer, your watermelon peperomia will be lush, bushy and healthy for many years to come.