Peperomia argyreia or peperomia watermelon is a perennial herbaceous flowering plant from the Piperaceae family, indigenous to South America. Despite its common name, the plant has no connection to the watermelon fruit – the name relates to the silver stripes, shape, and fleshiness of the leaves that grow on red stems. It grows almost 8 inches high and just as broad. Small green flowers bloom on 4-inch stems in summer.
The decorative nature of its leaves makes this plant an attractive variety to cultivate. The plant will grow rapidly and be very healthy in the right conditions.
This plant loves indirect bright light. If you grow it indoors, it needs a well-lit room to help encourage healthy growth of the watermelon variation of the leaves. Don’t expose it to direct sunshine as the leaves will become yellow.
You don’t have to worry as it can easily adjust to low-lit environments such as offices or living rooms with less light than its native home in the tropics. However, insufficient light also generates some issues such as the plant becoming leggy with stems prone to stretching longer than normal and leaves losing their patterns.
It has to be watered frequently, particularly when the topsoil has dried out. This usually is about once weekly and doesn’t require frequent watering in winter, about once in 2-3 weeks. While it loves watering, the roots should not be deprived of air by water-logging the soil. The plant is drought-tolerant by nature, storing water in its leaves to get them through dryer days.
The average humidity indoors of 40% is sufficient for this plant as it can adapt well to slightly drier indoor environments.
Regular misting now and then will help it thrive, particularly when the weather becomes warmer, as well as in winter when indoor heating dries the air.
If the leaves are drooping in the summertime, perhaps the humidity level is insufficient and you might have to use a humidifier or a humidity tray to supplement the misting.
As a native of the tropics, the plant does well in temperature ranges of 65-85°F with a low of 50°F. It dislikes temperature fluctuations. So it shouldn’t be directly exposed to air conditioners in summer and heaters during winters.
It must be planted in a rich, well-draining, and balanced potting mix. You can make a good mix by combining 2 parts of moss, 1 part of perlite, and 1 part of sand.
It doesn’t like its roots to be water-logged for too long as the roots will begin rotting and the plant will eventually die.
Repotting is usually stressful for most plants, so only do it when necessary. If you notice that the plant requires more space (roots appearing outside the pot), then it’s time for repotting it, but since it is a compact plant and likes to be root-bound, you will perhaps have to report it every 2 years or so. Repotting is also beneficial as the soil is refreshed and is essential for healthy growth.
When repotting the plant choose a somewhat larger pot than the former one. After removing the plant, discard old soil from the root ball and trim away any old roots and leaves if necessary. Now transplant it into the new container, topping up the soil and water well when done.
There are two methods in propagating this plant – leaf stem cuttings and leaf cuttings.
Leaf stem cutting:
Start by cutting off a leaf with a stem with a few leaves on it, place it in a container of water and keep it in a well-lit location. After a few weeks, when roots appear, transplant them into a container of moist soil.
Snip off a good-sized leaf and cut it horizontally in half and place it on a paper towel for a callus to develop. Insert the leaf, cut-side facing downwards, into moist soil and cover it to prevent moisture loss. Transplant it into a container of moist soil when new growth emerges.
Lastly, place plastic to prevent the moisture from leaving.
It grows rather slowly and needs just a moderate bit of feeding in the growing season. Fertilizing it with an organic fertilizer such as vermicast or vermicast tea is a good alternative to synthetic fertilizers. However, if you don’t have access to organic fertilizers, regular all-purpose fertilizer will also work at about ½ the recommended dose to prevent the buildup of salts.
Prune the plant to remove longish stems and remove dead leaves to improve the overall appearance of the plant as well as promoting bushier growth.
A healthy plant will have no pest infestation or suffer from diseases. Over-watering is the key cause of any problems the plant might face and if this is avoided, the plant will continue to thrive for a long time.
Secondly, proper lighting conditions are also important in keeping the plant healthy, thriving, and free from bugs. Too little light will make the unique markings disappear from the leaves.
Aphids, whiteflies, and mealybugs can infest the plant and damage it during its growing period. They can be exterminated with cotton swabs or a brush wet with rubbing alcohol. Repeat this until all the bugs have been exterminated as new pests might still hatch, so the plant has to be inspected often.
Do not stress the plant. Under-watering or over-fertilization can make the plant become a target for pests and diseases.
Leaves looking faded or dull suggests that the plant is suffering from sunburn. Move it away from direct sunshine.
Leaves drooping indicate that the plant is under-watered. Water it well and follow the recommended schedule for watering. You can also place it in a basin filled with water and allow it to absorb water. Take it out after a while and let it sit to drain out excess water afterward. Too much light also tends to dry out the plant faster.
If leaves are developing brown tips, it indicates that it is overwatered. Let the plant rest for some days before watering again