The watermelon peperomia aka Peperomia argyreia [pep-er-ROH-mee-uh ar-GY-ree-uh] is an herbaceous perennial native to South America (Brazil).
The variegated leaves resembling the patterns found on watermelon rinds earned the common name of “Watermelon peperomia.” It is one of the more popular Peperomia varieties.
The genus name “peperomia” comes from two Greek words: peperi (pepper) and homoios (resembling). “Argyreia” means silvery.
The plant looks like the true black pepper plant. It is a member of Piperaceae (pepper) family and list for growing in USDA hardiness zones 10 to 12.
Watermelon Peperomia Care Instructions
Size & Growth
When grown as indoor house plants, this easy care peperomia, low-growing plant reaches 6″ or 8″ inches tall. In the right environment, the plants are is quite vigorous, growing and reproducing quickly.
Flowering & Fragrance
The flowers of the watermelon peperomia are small, green and unscented. They appear on 3″ inch long, red flower spikes rising above the foliage.
Many growers of peperomia plants trim off the flowers. As a flowering plant the flowers are not attractive and rob the plant of energy which it could use to produce more attractive fleshy leaves with dark green stripes.
Light & Temperature
For the most part, in the United States, this plant is a houseplant. It is best to keep it in a sheltered location with bright indirect light.
To keep these warm weather plants happy, maintain a room temperature of 70° to 85° degrees Fahrenheit. These tropical plants do not like it when temperature’s drop.
These plants do well in bright light but do not handle direct sunlight. Even excessive indirect bright light causes the dark green veins on the peltate leaves (shaped like a shield) to become less prominent.
With too little light the entire leaf loses the “watermelon” silver variegation and becomes darker green. Peperomia thrives in an east facing window.
How Often To Water Peperomia Argyreia
Although water requirements are low, it is important to keep an eye on your watermelon peperomia plant.
When watering allow the top inch or so of soil to dry before watering again. Then thoroughly water the plant.
If the semi-succulent leaves droop or feel a bit thin, it may also be time to water.
Increase humidity levels higher during the spring and summer growing season.
CARE TIPS: Place the Peperomia watermelon plant on a tray of wet pebbles or keep a humidifier in the room.
Water less during the semi-dormant season (late fall and winter).
As with most houseplants, it’s best to under fertilize rather than over feed. Use a water-soluble liquid fertilizer solution at about half or one third the labeled recommended strength.
Feed plants about once a month during the growing season. Feed once every two or three months during the dormant season.
Soil Moisture & Transplanting
Peperomia does well in a rich, well-draining potting soil. A mixture of equal parts peat moss and perlite is an ideal potting mix.
When repotting Peperomia, be careful not to give it too much room. These plants like to be slightly root bound, so it’s best to opt for a pot that seems a little bit too small.
However, make sure the pot has a drainage hole.
Grooming And Maintenance
These plants do not tend to wander or stray. Pinch off dead leaves as needed. Cut back the flowers altogether if you prefer a leafy plant. Otherwise, cut them back after blooming is complete.
How To Propagate Peperomia Argyreia
It is almost impossible not to propagate the watermelon peperomia plant. Grow the plant from a leaf or stem cutting in soil or water.
To propagate plants from leaf cuttings, cut a leaf in half and press it into the soil. New plants will grow from the veins. The use of rooting hormone speeds the rooting process.
To propagate from stem cuttings, leave the stem on the leaf, and place it in clean water. Change the water every couple of days. You will soon see roots appear.
Growing from leaf cuttings in soil is the preferred method. The roots produced this way are stronger than those raised in water.
Watermelon Peperomia Pests and Diseases
This plant does not have any serious disease or insect problems. Like most houseplants, over watering, will lead to root rot problems.
Weak plants are susceptible to whitefly, spider mite, and mealybug infestation. More on killing mealybugs.
Providing the right balance of indirect light, water, humidity, and good ventilation helps prevent pest problems.
Read the PlantCareToday article on Peperomia (Radiator plants) Diseases and Pests
Suggested Uses For Watermelon Peperomias
In its native South America, this plant is a tropical forest ground cover. This colorful evergreen does well in tropical outdoor settings in partial shade.
As a house plant, you will have the greatest success by providing ample warmth, humidity and dappled light.