Watermelon Peperomia Care (Peperomia argyreia): Watering, Light and Leaf Propagation

Watermelon peperomia (Peperomia argyreia) is a small houseplant whose round, silver-and-green striped leaves look just like the rind of a watermelon. It fits on a desk, a windowsill or in a terrarium, and a single leaf is enough to grow a new plant.

How to identify watermelon peperomia

It forms a low, almost stemless rosette about 6–8 inches tall, according to the Missouri Botanical Garden and the RHS. The leaves are broadly ovate with a pointed tip, fleshy and waxy, up to about 3.5 inches long. Silver bands run between the veins, with dark green stripes along the main veins. Each leaf sits on a dark red stalk up to 5 inches long.

NC State Extension points out an unusual feature: the leaf is truly peltate, meaning the stalk attaches to the underside near the middle of the blade rather than at its edge. In summer, thin spikes of tiny greenish to cream flowers rise just above the foliage on red stalks. They’re interesting but not showy.

Kew’s Plants of the World Online now accepts the name Peperomia argyraea W.Bull. Peperomia argyreia, Peperomia sandersii and Peperomia arifolia var. argyreia are synonyms. The RHS, the Missouri Botanical Garden and most sellers still use argyreia, and so do we. The species name means “silvery.” It is native to northeastern and southeastern Brazil.

Despite the common name watermelon begonia, it isn’t a begonia: peperomias belong to the pepper family (Piperaceae). It’s easy to tell apart from the baby rubber plant, which has stiff green or variegated leaves on short stalks and branching stems.

Light

NC State Extension and the Missouri Botanical Garden both recommend bright, indirect light and no direct sun. An east-facing window works well, or a spot set back from a south- or west-facing one. For this species the RHS suggests giving it full light in winter, when the sun is weak.

The University of Missouri says it tolerates lower light for several months without stress. Over the long term, though, the RHS notes that too much shade makes peperomias sparse and straggly.

Watering

Watermelon peperomia needs more careful watering than the succulent peperomias. The University of Missouri calls it a fine line: the leaves aren’t fleshy enough for the plant to dry out completely, yet it suffers if kept too wet. Water when the mix is dry a couple of inches down.

NC State Extension sums up both extremes: overwatering causes root rot, underwatering causes wilting. The Missouri Botanical Garden recommends watering moderately but consistently and cutting back from fall to late winter. The RHS says water moderately in summer and sparingly in winter. Always empty the saucer. For the general technique, see how to water houseplants.

The RHS also notes that peperomias are sensitive to fluoride in tap water. If you see brown tips, try rainwater or filtered water.

Potting mix and repotting

The RHS recommends a loose, free-draining mix, for example two parts peat-free ericaceous compost, one part perlite and one part medium orchid bark. The University of Missouri suggests adding perlite or orchid bark to a standard potting mix and prefers clay pots.

This is a slow grower, and NC State Extension says it thrives when pot-bound. Repot only when roots come through the drainage holes, usually after two or three years, and do it in spring. Choose a pot just slightly larger, or the mix will stay wet too long.

Humidity and temperature

The Missouri Botanical Garden says it likes high humidity in summer, and the RHS recommends it for terrariums and bottle gardens. In an ordinary room, a pebble tray helps, or group it with plants that have similar needs, as NC State Extension suggests.

The RHS recommends about 65–86°F (18–30°C) for peperomias, and the University of Missouri a minimum of 50°F (10°C). NC State Extension specifically warns against cold drafts, so keep it away from leaky windows in winter.

Fertilizing

Feed only during active growth, roughly spring to early fall. The RHS’s general peperomia guide suggests a half-strength liquid fertilizer every two weeks from April to October. Clemson Extension recommends only an occasional low-strength feed. A slow grower uses little, so err on the side of less.

Propagation step by step

NC State Extension recommends division and leaf cuttings; the RHS also lists removing offsets and sowing seed. The leaf-cutting steps below follow Clemson Extension. For other methods, see houseplant propagation methods.

Leaf cutting:

1. In spring or summer, choose a healthy, fully grown leaf.
2. Cut it off with a clean knife, keeping at least an inch of leaf stalk.
3. Insert the stalk into moist rooting mix so the leaf stands upright.
4. Keep it warm, in bright light without direct sun, and keep the mix only lightly moist.
5. New plantlets form at the base of the stalk. Once they have their own leaves, separate them and pot them individually.

Division:

1. Slide the plant out of its pot and gently shake off the mix.
2. Pull the rosette apart into sections, each with its own roots and several leaves.
3. Pot them in small containers of fresh, well-draining mix and water lightly.

Cultivars

The silver striping is the species’ natural pattern, not variegation. NC State Extension lists two cultivars:

• ‘Harmony’s Gold Dust’: leaves speckled with gold, a true variegated form. The source doesn’t state the type of variegation.
• ‘Costa Rica’: has a maroon dimple at the base of the leaf.

Common problems

Symptom	Cause	Fix
Stalks soft and dark at the base, plant collapses	root rot from overwatering	take healthy leaves as cuttings, repot the rest into drier mix
Wilting, limp leaves	underwatering	water thoroughly and don’t let the mix dry out completely next time
Yellowing leaves	constantly wet mix	water less, empty the saucer
Scorched patches on leaves	direct summer sun	move to indirect light
Sparse, leggy growth	too little light	move closer to a window
White cottony tufts on stalks	mealybugs	see mealybugs on houseplants
Brown bumps on leaves	scale	scrape them off, isolate the plant
Clusters of small insects on new leaves	aphids	rinse the plant, remove badly infested leaves

The Missouri Botanical Garden also mentions spider mites and whiteflies.

Toxicity

The ASPCA lists watermelon peperomia, under the name watermelon begonia, as non-toxic to dogs, cats and horses, and NC State Extension says the same. The sources don’t cover effects on people.