This is a complete beginner's guide to growing and caring for the watermelon peperomia plant.
Therefore, if you've ever wondered how to add these beautiful plants to your indoor plant collection, this is the perfect place to start your research.
With patterns on the leaves resembling watermelon rind, it's undoubtedly one of the most eye-catching houseplants in existence.
Watermelon peperomia plants (Peperomia argyreia), previously known as Peperomia sandersii, are close relatives of true black pepper (Piper nigrum) and distant relatives to the popular pothos plants, and just as easy to grow and maintain indoors.
In today's post, we're going to discuss everything you need to know to successfully grow and care for these plants including where to buy watermelon peperomia plants, their propagation, and the common problems to watch out for.
Let's begin with a brief introduction to Peperomia argyreia.
Introduction to Watermelon Peperomia Plants (Identification)
Peperomia argyreia is a tropical species of perennial plant with evergreen foliage.
It belongs to the family Piperaceae, along with other common plants such as black pepper and kava.
Peperomia argyreia derives its name from the Greek word “argyros” meaning silver, which refers to the glistening pattern on the leaves.
The plant grows a lush, green stem that can reach up to 6 - 8 inches in height with an equal spread, however, multiple stems growing from a single root system are quite common too.
These upright stems support ovate or lanceolate leaves that measure around 2-3 inches in length and grow in whorls along the stem.
The leaves of the watermelon plant are thick, shiny, and variegated green with silver streaks running through them, which together gives the plant its distinctive look which resembles the surface of a watermelon.
Each round, glossy, fleshy leaf that grows to 3.5” long is attractively striped with green and silver in a manner reminiscent of the watermelon rind. Leaf stems are an attractive red. While the plant will occasionally produce some interesting flowers, it’s mainly appreciated because of the leaves.
These plants have been around for many years and remain as popular as ever due to their unique flower shapes and variegated leaves.
Plant profile (noteworthy characteristics)
Common Name(s): Watermelon peperomia, Watemelon plant, Watermelon begonia, Peperomia Sandersii
Botanical Name: Peperomia argyreia previously known as Peperomia sandersii
USDA Hardiness Zones: 10 - 12
Mature height: 6 to 8 inches tall
Mature spread: 6 to 8 inches wide
Growing habit: Erect and bushy
Blooming: Seasonal flowering with a white-cream showy flower spike which is insignificant.
Native area: South America
How to Easily Identify the Watermelon Peperomia
- Check the leaves to confirm if they’re smooth with variegations like a watermelon.
- Inflorescences are numerous creamy spikes.
- The stems and petioles are commonly red.
- Peltate leaf attachment.
Peperomia argyreia is non-toxic to humans and animals, however, ingesting large quantities can cause stomach irritation.
The sap in its leaves may cause skin irritation when touched or ingested, so it’s best to handle the plant with gardening gloves.
Where to buy Peperomia argyreia plants
Peperomia argyreia is widely available in nurseries and garden centers, especially in areas that have a warm climate year-round, such as Florida or California.
You can also purchase watermelon peperomia plants online from various retailers and plant distributors. A good example is Amazon.com. We’ll keep updating this section of the article from time to time with more sellers.
Therefore, if you have any peperomia plant distributors in mind you can share them so that we can update them.
How to propagate Peperomia plants
Propagating Peperomia argyreia is easy and can be done by taking cuttings of the stem or leaves, rooting them in water, soil, or a potting mix for succulents.
The stems on these plants root quite easily.
However, if you prefer to start plant propagation from an aerial stem cutting (a leafy branch), it's best to let the cut end dry out and callous before inserting it in the potting mix.
This ensures that no sap remains on the surface of the plant which may inhibit root growth when introduced to soil or water.
If you want to get the best results, use an appropriate rooting hormone to give your plantlets a good head start and boost overall plant growth and development.
Also, it’s important to use equipment such as shears or scissors that you’ve thoroughly sterilized to avoid any infections.
Select an appropriate potting mix
Peperomias like a light potting mix since their roots are often prone to rot. Therefore, it’s vital to select appropriate potting soil.
If possible amend your potting mix with some orchid bark, worm compost, and coco coir instead of peat moss. Coco coir can hold water without sacrificing aeration which is key when it comes to drainage.
If all this sounds too complicated for you, any commercial cactus mix (succulent and cacti potting mix) will still work fine.
Whatever you decide, don’t use garden soil or topsoil because it contains too much organic matter which leads to the development of mold and fungus when exposed to high humidity. These conditions will facilitate root rots in your peperomia plants.
Expose your Plants to bright indirect sunlight
If you’re planning to grow your peperomias indoors, keep in mind that the plants require a lot of bright indirect sunlight.
However, be careful not to expose the plant to direct sunlight because the leaves may burn. Besides, while other types of peperomias thrive in bright light, too much of it will force the watermelon begonia to fade the variegated color.
Furthermore, these plants can tolerate low light for several months without any noticeable stress.
Ideally, it's best to place it in an East-facing window or another location where it will receive three or more hours of morning sunlight.
If you want to grow the plants outdoor, make sure you grow them under the shade or where the sun is filtered. Here’s a list of other shade-loving perennials.
Watering your watermelon begonia
It's important to leave the soil slightly dry between watering, which means avoiding frequent waterings.
If you're growing watermelon peperomia plants in a small container, it's best to let the soil dry out completely before re-watering.
On the other hand, if you notice that leaves are looking droopy, it’s time to give your plants a thorough drink – which means until you see water coming out of the drainage holes.
Temperature and Humidity
Peperomia argyreia is a tropical plant that grows well in warm indoor conditions (average room temperature of 15C - 28C or 60F - 82 F).
Peperomias are sensitive to freezing temperatures. Hence, if you take your plant outdoors during warm weather, bring it in as soon as nighttime temperatures drop to 60 to 65 F.
Although these plants require high humidity levels (> 50%) and benefit from misting the leaves regularly, most average indoor humidity will be sufficient for them to thrive.
However, if you suspect your indoor humidity is way too low, you can increase it by grouping the plants together, placing them in or near your bathroom, placing the plants in a saucer full of wet pebbles, or using an indoor plant humidifier.
Watermelon peperomia plants can be fertilized once every month during their active growth period (spring and summer) with a standard houseplant fertilizer.
You can also use natural organic fertilizers, such as compost or manure tea.
However, it's best to steer clear of synthetic fertilizers because the high amount of salts they contain may damage the plant.
Repotting Watermelon Peperomia
Peperomia argyreia doesn’t require frequent repotting.
You can move your plant into a larger container once every two years or if you notice the roots coming out the drainage holes, but otherwise it's not necessary because peperomias like to be pot-bound.
Cleaning the leaves
It's important to wipe the leaves frequently with a wet cloth to remove dust and dirt that can damage their glossy surface.
Pests and Diseases Control
Mealybugs, spider mites, and whiteflies are the most common pests that affect Peperomia argyreia. When a plant is infested with these bugs, it's best to isolate it from the other plants in your collection to avoid any further spread.
Thankfully, except for the occasional root rots, these plants are not susceptible to diseases. You can manage root rots by following good watering practices.
Common problems growing watermelon peperomia plants
1. Watermelon peperomia drooping leaves
If you notice that the leaves of your plants are looking droopy, 80% of the time it’s because the potting soil lacks moisture as a result of under-watering.
You may need to check the potting mix if it’s dry and water where necessary. However, if there is sufficient moisture present in the mix, then your watermelon begonia may be suffering from root rot as a result of overwatering.
In such a case, you need to expose your plant to sufficient aeration to enable the mix to dry up. For instance, bring your plants outdoor if the conditions are conducive.
2. Watermelon peperomia leaves curling
Curling of the leaves in peperomias could mean several things. The first and most common is the lack of sufficient water in the soil. The second reason is exposure to low light levels for a prolonged period.
The last and often accompanied with deformed leaves is either an attack by bugs or a deficiency or both. For instance, if your peperomias are suffering from calcium and magnesium, they will attempt to communicate with you by curling their leaves.
Apply a balanced houseplant fertilizer rich in Calcium and Magnesium where possible.
3. Brown spots on the leaves
There are a lot of contradicting explanations out there on why there are brown spots on the leaves of watermelon peperomia.
I’ll, therefore, try to explain this as best as I can.
For starters, in rare cases the brown spots form in a ring-like manner, then the plant could be suffering from peperomia ring spot which is caused by a virus transmitted in unhealthy cuttings during propagation.
The other disease could be leaf spot caused by leaving water on the leaf surface for too long.
If that’s the case, discard all the affected plants and propagate fresh ones from healthy plant cuttings.
Overwatering or severe underwatering could also cause the leaves on your peperomia to develop brown spots.
4. Peperomia leaves fading
If you notice that the watermelon-like variegation on leaves is beginning to fade, it means that you’re exposing your peperomia plants to too much bright sunlight.
To correct this problem, place the plants where they can receive bright indirect sunlight preferably the morning sunlight.
5. Peperomia leaves yellowing and dying
Yellowing of the leaves is almost always a result of too much water in the soil. If it persists, the leaves will fall off the plant and eventually die.
To correct this problem, cut off the yellow leaves sparingly since they don’t look that good anyway. Go slow on watering and if the plant is adversely affected cut off the healthy part and re-propagate to start afresh.
This way, you could save your dying watermelon peperomia.
6. Watermelon peperomia leaves splitting
As already established, peperomias are humidity-loving plants. But they just don’t love the humidity, instead, they need it to thrive and maintain those beautiful leaves.
If they don’t get enough humidity especially when respiration is high, the leaves dry out and then split. Frequent misting of the leaves when the weather is hot will help to prevent this problem.
While watermelon peperomia is quite a breath-taking plant that is easy to grow and care for, most people especially first-time owners find it difficult to keep the plant in top shape.
However, with this guide, you’ll be able to not only unleash your green thumb but enjoy while at it. If you have to forget everything you’ve read in today’s post, remember these 3 things:
- Peperomias prefer a light potting mix that drains well.
- They prefer bright but indirect light preferably in the morning.
- Check your watering (Re-read that part)
I hope you’ve enjoyed reading this article as much as I enjoyed writing. In which case, I’d appreciate it if you could share with your inner circle.