Ever see a houseplant and think someone painted a watermelon rind on every leaf? That’s the watermelon peperomia, a small, tidy plant with silver-and-green striped leaves on bright red stems.
It’s a tropical evergreen with an erect, bushy habit, native to Brazil, that grows up to 8 inches tall. Its leaves are smooth, waxy and striped like a watermelon, and they attach to their red leaf stalks in the middle of the leaf (a rare “true peltate” attachment) rather than at the edge.
It’s a member of the pepper family, Piperaceae. The name Peperomia comes from the Greek peperi (pepper) and homoios (resembling), a nod to its relative, the black pepper plant, Piper nigrum. The watermelon peperomia itself doesn’t look much like black pepper; it’s the family tie that the name points to.
Watermelon Peperomia Quick Care Tips
- Botanical name: Peperomia argyreia (the name on most plant tags); it’s also spelled Peperomia argyraea
- Older name: Peperomia sandersii
- Common names: Watermelon peperomia, watermelon begonia (it is not a begonia), watermelon plant
- Pronunciation: peh-per-ROH-mee-ah ar-jy-RAY-ah
- Family and origin: Piperaceae (pepper family); native to Brazil
- Growability: Easy, low maintenance
- Hardiness zones: USDA 10a to 12b
- Size: Up to about 8 inches tall
- Growth rate: Slow
- Flowering: Thin, cream-colored flower spikes 2 to 4 inches long in spring and summer; not showy
- Light: Bright, indirect light; no direct sun
- Temperature: Warm rooms, about 65 to 86°F and always above 50°F; protect from cold drafts; outdoors only once nights stay at 60°F or higher
- Humidity: Average home humidity is fine; a humidifier helps in winter
- Soil: Well-drained houseplant or cactus potting mix
- Water: Let the soil dry out between waterings; water less in winter
- Fertilizer: Low-strength liquid fertilizer occasionally in spring and summer, or slow-release granules once a year
- Pests and problems: Mealybugs, scale, spider mites, whiteflies, aphids and fungus gnats; root rot from overwatering; leaf spot
- Propagation: Leaf cuttings with a piece of leaf stem, stem cuttings or division
- Pet safety: Non-toxic to dogs and cats
Watermelon Peperomia Care Instructions
What’s in a Name?
You’ll find this plant sold as Peperomia argyreia. Extension references now spell it Peperomia argyraea and list Peperomia argyreia and Peperomia sandersii as names it was previously known by. Same plant, slightly different spelling. “Watermelon begonia” is another listed common name, but it’s a peperomia, not a begonia.
Size and Growth
Watermelon peperomia stays small. It’s a small, bushy plant that grows up to about 8 inches tall, which makes it ideal for an office or a small space.
Don’t expect it to race. Its growth rate is slow. A foliage research note (Peperomia Production Guide) describes it as a rosette type, with dark green leaves, silvery-gray zones radiating from the leaf center, slightly cupped leaf blades, and long reddish leaf stalks.
Flowering
The flowers are a bonus, not the show. It sends up erect spikes 2 to 4 inches long covered in minute, white to cream-colored flowers. Peperomia flower spikes appear while the plant is actively growing in spring and summer, are considered unattractive, and are said to resemble a rat’s tail. Don’t be surprised if yours never blooms, though: as houseplants, peperomias typically will not flower.
Plenty of growers snip them off. Removing the flower spikes lets the plant focus its energy on making leaves. If you like them, leave them, and cut them off once they fade.
Light
Bright, indirect light suits watermelon peperomia best. Place peperomias where they get indirect light from an east- or south-facing window; they can even tolerate somewhat low light near a large north-facing window.
Keep it out of hot, direct sun. If a peperomia gets direct sun, the leaves may scorch.
Temperature
Treat it like the tropical plant it is. Peperomia’s other common name, radiator plant, refers to its preference for warm conditions, so protect the plant from cold drafts. Keep it away from drafty doors, cold windows in winter and air-conditioning vents. For peperomias in general, the RHS gives a warm room of about 65 to 86°F (18 to 30°C) and says to keep them always above 50°F (10°C).
Outdoors, it’s a plant for frost-free gardens only: USDA zones 10a to 12b. Everywhere else, you can move peperomias outdoors for the summer once night temperatures are consistently 60°F or higher, starting them in deep shade and keeping them in a bright but shady spot out of direct sun.
Watermelon Peperomia Watering
Overwatering is the mistake to avoid with this plant. Clemson Extension puts it plainly: “Peperomia prefers to dry out between waterings. If it is overwatered, it will drop its leaves.”
NC State Extension‘s watermelon peperomia page is more specific: let the soil dry to the touch at the top before watering, and water less in the winter months. It says the plant is intolerant of both wet soil and very dry soil. Too much water causes root rot, and too little makes the plant wilt.
When you water, water until it drains, then let the pot finish draining before you set it back in its saucer. Don’t leave it sitting in water. It’s best to err on the dry side when growing peperomia, and the University of Arkansas Cooperative Extension Service says peperomias have a small root system and are easy to overwater, especially in winter when growth is slow.
Humidity
Average indoor humidity is usually fine. Peperomias can thrive in the humidity levels of most homes, but if the home is very dry, consider a humidifier, especially in winter.
A pebble tray or a humidifier raises humidity without wetting the leaves, and dry leaves matter: fungal leaf spots can be prevented by keeping the leaves dry when you water.
Fertilizer
Go easy on the food. Fertilize peperomia only when it is actively growing in spring and summer, using a low-strength liquid fertilizer occasionally during the growing season, or a slow-release granular fertilizer once a year. Follow the label for the amount, and skip feeding through fall and winter.
There’s a good reason to under-feed rather than over-feed. Peperomia roots are very fine and easily damaged by too much salt in the root zone, and the roots often die back before you see symptoms in the leaves.
Soil and Repotting
Drainage comes first. Use a well-drained houseplant or cactus potting mix, or a moist, well-drained mix of loam and sand. Peperomia roots are very sensitive to waterlogged soil, and commercial growers use well-drained peat-lite mixes with coarse particles such as perlite to give the roots air.
Don’t rush to repot. Watermelon peperomia won’t need repotting often because it thrives being pot-bound, and peperomias are usually best grown in relatively small pots. The plant can stay in the same pot for several years, and when you do move it, use a pot only slightly larger than the grower’s pot. Whatever you choose, make sure it has a drainage hole.
Grooming and Maintenance
This is a low-fuss plant. Trim off old leaves when needed, and prune a stem just above a leaf node if you want the plant to branch and look fuller. Pinch off any yellow or damaged leaves to keep it tidy.
Propagating Watermelon Peperomia
Want more watermelon peperomias? The plant is usually propagated from leaf cuttings, and division works too. Terminal (tip) stem cuttings can be used with all peperomia types. Iowa State University Extension names peperomia as one of the houseplants that root well from leaf petiole cuttings (a leaf with its leaf stem attached).
The leaf-cutting steps are simple:
- Remove a leaf with at least an inch of the petiole (leaf stem).
- Insert the leaf stem into a rooting medium.
- New plants form at the base of the petiole.
- Once they do, separate them and pot them up.
A few more details: leave 1 to 1½ inches of leaf stem, treat the end with rooting hormone if you like, and set the cutting in at a 45-degree angle. Keep it in bright, indirect light with high humidity (a loose plastic bag or dome helps). For rooting cuttings, an air temperature between 65°F and 75°F is ideal. Roots usually form in three to four weeks, and small plantlets appear at the base of each leaf stem in six to eight weeks.
Can you root it in water? Many houseplants will. But roots that form in water are coarser and not well adapted to potting soil, so water-rooted cuttings may wilt, drop leaves or brown once potted. Rooting medium is the better bet.
Related: How To Propagate Peperomia Baby Rubber Plants
Watermelon Peperomia Pests and Plant Diseases
Good news: watermelon peperomia has no serious pest or disease problems. It can still pick up the usual houseplant pests. Watch for mealybugs, scale and aphids on this plant, plus spider mites, fungus gnats and whiteflies on peperomias in general. Check the undersides of leaves and the leaf stalks now and then.
For mealybug infestations, the University of California Statewide IPM Program (UC IPM) says that on small infestations on houseplants, a 70% (or less) solution of isopropyl (rubbing) alcohol in water can be dabbed on the mealybugs with a cotton swab, after testing it on a small part of the plant 1 to 2 days beforehand to check for leaf burn. It says insecticidal soaps, horticultural oils and neem oil applied directly to young mealybugs can reduce their numbers. Not every source agrees on alcohol: UF/IFAS Gardening Solutions says alcohol is phytotoxic (it causes leaf burn and other plant injuries) and warns that dish “soaps” are detergents, not true soaps. If you spray, use a product labelled for the job and follow the label.
Water causes more trouble than bugs. Root rot, caused by overwatering, is the most common disease of peperomia, and it can quickly occur on this plant. Leaf spots are the other thing to watch. Phyllosticta leaf spot occurs on watermelon peperomia as dark brown to black, dry spots with rings, commonly found on the leaf margins and spreading across the leaf; remove infected leaves and keep the foliage dry.
Related: Peperomia (Radiator plants) Diseases and Pests
Is Watermelon Peperomia Safe for Pets?
Yes. The ASPCA lists watermelon peperomia (Peperomia argyreia) as non-toxic to dogs and cats, and most peperomias are considered safe for pets. Non-toxic doesn’t mean edible, though, so keep it where pets and small children won’t chew on it.
Suggested Uses For Watermelon Peperomias
Watermelon peperomia is a natural desk or tabletop plant. It’s used as a specimen or desktop plant and looks better grouped with plants that have similar care needs, and its compact size makes it ideal for an office or a small space.
In frost-free gardens (USDA zones 10a to 12b), it can grow outdoors as a small groundcover in a shady spot. Everywhere else, enjoy it indoors, or give it a summer outdoors in a bright, shady spot once nights stay at 60°F or higher.
Where does your watermelon peperomia live, on a desk, a shelf or a windowsill? Tell us below!
Frequently Asked Questions
Is watermelon peperomia easy to care for?
Yes. It’s rated easy to grow and low maintenance, with no serious pest or disease problems. The main thing to get right is water: peperomia prefers to dry out between waterings and drops its leaves when overwatered. Give it bright, indirect light, a well-drained houseplant or cactus mix and a pot with a drainage hole, and let the pot drain after watering.
How often should I water a watermelon peperomia?
Water when the top of the soil is dry to the touch, and water less in winter. Peperomia prefers to dry out between waterings, and overwatering causes leaf drop and root rot, its most common disease. Let the pot drain fully before setting it back in its saucer.
How much light does watermelon peperomia need?
Bright, indirect light is best. An east- or south-facing window works well. Peperomias can tolerate somewhat low light near a large north-facing window, but direct sun may scorch the leaves.
How do you propagate watermelon peperomia?
Use leaf cuttings. Watermelon peperomia is usually propagated from leaf cuttings. Remove a leaf with at least an inch of its leaf stem and insert the stem into a rooting medium; new plants form at its base. Roots usually form in three to four weeks, with small plantlets in six to eight weeks.
Is watermelon peperomia toxic to cats and dogs?
No. Watermelon peperomia (Peperomia argyreia) is listed as non-toxic to dogs and cats, and most peperomias are considered safe for pets. Non-toxic doesn’t mean edible, so it’s still wise to keep the plant where pets and small children won’t chew on it.