The Watermelon Begonia is also known as the Pellionia Repens. This is a rare vining plant that will develop long stems.
As such, some people refer to it as the trailing Watermelon Begonia.
Its long stems make it great as a hanging plant or spilling plant. Of course, you can also keep it in a container and let its vines sprawl over.
Each vine is adorned with lots of small green lime, purple black or red and burgundy colored foliage.
It is native to Southeast Asia.
How do you grow Watermelon Begonia? Keep soil evenly moist but do not overwater or leave the soil wet. It is prone to root rot.
The plant grows best in bright, indirect light and high humidity. Feed it during the warmer months as well to achieve optimal growth.
Watermelon Begonia Plant Care
Pellionia Repens Light Requirements
The Pellionia Repens thrives in medium to bright indirect light indoors. Outdoors it will grow best in partial sun or partial shade.
That side, the plant does well in a wide variety of lighting conditions.
This means it easily to position in different places in the house.
Outdoors, is also makes it easier to find a good spot for the plant.
However, the one thing you want to avoid is intense, direct sunlight. It cannot tolerate more than 2 or so hours of this on a daily basis.
The reason is that the Watermelon Begonia is a vining plant that is native to the tropical forest floor.
Because it is an understory plant, it is used to getting the shade of larger trees and plants.
This means that it is not used to the harsh or intense rays of the sun. Instead, it receives filtered or dappled light that gets through the leaves and branches overhead.
Its dark colored leaves also tell you that it can tolerate low light.
That’s because they are filled with chlorophyll which is the pigment that makes leaves colored green. More importantly, chlorophyll is the compound the absorbs light from the environment
The plant then uses the light the leaves collect for photosynthesis.
As such, the abundance of chlorophyll means the leaves are able to get lots of light even in low light conditions.
Thus, allowing the plant to tolerate less light than similar plants with light green foliage or variegations.
This lets you place the plant in a north facing window in your home without any problems.
But to get optimal growth, bright, indirect light from an east or west facing window is ideal.
Pellionia Repens Temperature
The Watermelon Begonia can also tolerate a wide temperature range.
As long as you keep the plant in an environment between 55 to 90 degrees Fahrenheit, it will do well. Again, this makes it easy to care for the plant indoors.
The wide temperature range allows the plant to easily adapt to many different conditions.
But like light, there’s one thing you need to watch out for here.
This is low temperature.
Its temperature tolerance is 50 degrees Fahrenheit.
Additionally, the Pellionia Repens is a frost tender plant. This means it cannot tolerate freezing conditions or winter weather.
As such, don’t leave the plant outdoors if you have frost or freezing temperatures in winter.
Instead, the watermelon begonia prefers USDA Hardiness Zones 10 and 11 since these areas have moderate to warm, sunny weather from November to March.
In you live in these regions, you can keep the plant outdoors all year round.
Pellionia Repens Humidity
The Pellionia Repens not only enjoys warm weather, it also likes humidity. Ideally, it needs moderate to high humidity between 40% to 90%.
Given a choice, it prefers the middle to higher end of that range.
However, as long as you keep humidity at 40% or higher, it won’t be a problem and the plant will happily grow.
This is why many growers will keep their Pellionia Repens in a terrarium.
The plant appreciates the high humidity that environment offers.
On the other hand, you do need to check how much humidity your home gets indoors. Similarly, depending on where you live, the surrounding humidity may or may not be high enough for the plant.
Note that indoor humidity is always lower than outdoor humidity.
This means it is not a good idea to use the weatherman’s humidity forecast for your area as you home’s humidity.
If you’re not sure what humidity it indoors, a hygrometer is an low cost, portable device you can get to check humidity from room to root.
It also lets you know when humidity drops so you can take action.
If indoor humidity is too low, you can get a humidifier, keep the plant in the bathroom, mist it a few times a week or set up a pebble tray.
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How Often to Water Watermelon Begonia
The Pellionia Repens likes consistently moist soil. This allows the plant to stay healthy and grow properly.
As such, it likes regular watering.
But while the watermelon begonia enjoys moist soil, it cannot tolerate, wet, soggy soil. Similarly, it is not a fan of going completely dry.
So, avoid both of these extremes.
Of the two, you need to watch out more for too much water.
That’s because excess moisture can damage or even kill the plant.
Overwatering will keep the roots wet for long periods of time. Unfortunately, roots need oxygen as much as they need water.
So, when the soil is wet and filled with excess water especially at the root system level, then end up suffocating.
That’s because they cannot breathe with all the water covering them.
When this happens, they die and root rot occurs.
On the other hand, while the Pellionia Repens does not like going completely dry, it can bounce back faster from this state after you add water.
As such, to make sure you don’t overwater your watermelon begonia, always wait for the top inch of soil to dry out completely before adding more water.
To check, stick your finger down to the first knuckle and feel the soil at that depth.
It there is any moisture at all, even a little, don’t water.
Only water when it is completely dry to the touch.
Watermelon Begonia Potting Soil
The watermelon begonia needs well-draining potting soil. The goal is to choose a potting mix that is fast draining but will hold some moisture.
This comes from its watering needs.
It does not like going dry but cannot tolerate overwatering. Thus, the soil needs to hold some moisture to keep the roots hydrated.
But it has to be able to quickly remove excess moisture to avoid overwatering and waterlogging.
Additionally, it also likes rich soil which will help it get nutrients.
The good news is that there are many different kinds of soil mixes you can make to achieve this.
You can use a combination of coco coir with perlite or orchid bark. Then add worm castings to provide the slow-release organic nutrients.
If you already have peat at home, you can use that combined with perlite as well.
The key is to have some component to provide moisture retention and something that will increase drainage.
The final piece of preventing overwatering is to use the right pot.
Here, make sure the container you use has drainage holes to allow any excess moisture that drains from the soil to exit the pot and not just pool at the bottom.
Does the Pellionia Repens like to Climb?
The Pellionia Repens is a vining plant that can climb. But it prefers to weave it way around things or drape downwards.
This is why it is called the trailing watermelon begonia.
This means the plant is not a natural climber. Although it can climb a little it does not need a support or pole to go up on like some other climbing species.
Pellionia Repens Fertilizer
Feeding the Pellionia Repens is straightforward. And all you need to do is make sure the plant gets the nutrients its needs.
As such, there’s no need to overthink this section.
In fact, growers who overthink it or try to maximize feeding usually end up overdoing it.
Like water, stay on the conservative side when it comes to fertilizer.
Apply an all-purpose houseplant fertilizer once a month during spring and summer. Dilute the dose by half strength if you keep the plant in a pot indoors.
If you’re growing it outdoors in the ground, use the full strength the manufacturer suggests.
Once fall arrives stop feeding and don’t fertilize in winter either.
Pellionia Repens Pruning
The Pellionia Repens will grow to around 4 to 5 inches high. But its vines will extend and reach over two feet in length extending all over the plant.
If is also a fast, aggressive grower.
How big it will actually get and how much pruning you will need to do will vary based on where you plant it.
In a terrarium, the plant stays fairly small. It also won’t grow as long. Instead, it will focus more on its fullness.
Still, you will need to prune it every so often.
This occurs as it can get very bushy.
On the other hand, in a container, its vines will extend outwards. These will go out in all directions. So, you will need to prune on a regularly basis.
The vines can get messy and grow all over one another.
In a hanging basket, mess is less of an issue since all the leaves trail downwards.
How to Propagate Watermelon Begonia
The Watermelon Begonia is easy to propagate. And the simplest way is via stem cuttings or vine cuttings.
Here, you’ll be making use of its long vines.
Therefore, if you’re thinking of propagating, don’t throw away the vines that you pruned.
The best time to propagate the plant is in spring. And only propagate a healthy plant, not when it is sick or having problems.
Here’s how to propagate Watermelon Begonia from stem cuttings.
- Choose healthy stems with at leas 4 to 6 leaves on it. You’re looking for vines at least 3 inches or longer.
- Take a sterile pair or scissors and snip the vine just under a node.
- Then plant the vine cutting into a 4-5 inch pot filled with well-draining soil. Make sure that the pot has drainage holes at the bottom.
- Water the soil and keep it moist. Don’t let the soil dry completely. But don’t let overwater it as well.
- Keep the pot in bright, indirect sunlight in a spot that is warm with good humidity.
How to Repot or Transplant Watermelon Begonia
The watermelon begonia does not need regular repotting. In most cases, it only needs to moved to a larger container every 3 years.
However, the best way to tell is to check the bottom of the pot.
Once roots are poking out through the holes at the bottom of the pot, it means they are looking for more space.
Repot in spring
When doing so, only move the Pellionia Repens to a pot one size larger. And replace the potting mix with a refresh one.
Is It Toxic/Poisonous to Humans, Cats & Dogs
The watermelon begonia is non-toxic to people and animals. This means there is no risk of poisons even if your cat or dog consumes some the leaves.
But that does mean that it is okay.
In most cases, your pet will gag and end up vomiting to get the plant out later on.
Watermelon Begonia Problems & Troubleshooting
Mealybugs, fungus gnats, scale and vine weevils are common pests that will attack the plant.
These are very tiny bugs are difficult to spot until they’ve done their damage or grown in number. The also like hiding on the undersides of leaves on in the soil.
As such, it is important to check the plant regularly for any pests.
This will allow to treat them before they turn into bigger problems.
Similarly, the watermelon begonia is prone to certain diseases.
These include root ort, powdery mildew, southern blight and leaf spot disease. Most of these affect the leaves. Although root rot happens under the soil and directly affects the roots.
However, they all occur due to excess moisture in one way or another.
With root rot it is keeping the soil wet or waterlogged. For the leaf infections it is wetting the leaves without allowing them to dry fast enough.
As such, these are preventable.