Watermelon Peperomia plants have incredible leaves and it’s always devastating to see that some of them are starting to turn yellow. But don’t fear, we have figured out exactly what can cause yellow Watermelon Peperomia leaves as well as what you need to do to fix the issue and prevent it from happening again. If you have caught the issue fairly early then you should have a good chance at getting your plant back to full health.
The most common cause of yellow Watermelon Peperomia leaves is overwatering
And the major consequence of this is root rot. Once the roots have started to rot in waterlogged soil, it will prevent the plant from getting the needed moisture and nutrients.
If you think that your Watermelon Peperomia is suffering from overwatering and root rot, the best thing to do is to take your plant out of its pot immediately and inspect the root system. Carefully trim away any rotten roots as this will encourage the new healthy roots to grow. If the potting mix is still soggy and waterlogged, replace it immediately. Don’t wait for it to naturally dry out as this risks causing more harm to your Watermelon Peperomia and cause more yellow leaves.
Over the next few weeks, you need to water your Watermelon Peperomia less than you were doing before so that it can start to recover. Using a moisture meter is a great way to know when it’s time for a water. You will also want to adjust your watering schedule depending on the seasons, to ensure that you are cutting down on watering over the colder, darker months of autumn and winter.
Top tip: to avoid the roots of your plant sitting in water for days, remove any excess water that has run out of the drainage holes into your saucer or planter.
Sometimes it may not be your watering schedule or overwatering that is causing your Watermelon Peperomia to develop yellow leaves, but the poor draining of the soil and pot. You can very easily increase the amount of drainage in your Watermelon Peperomia by mixing in a small amount of perlite, this will make it far easier for water to flow through and out of the drainage holes of your pots. Oh, that’s another thing, make sure your pot has drainage holes!!.
Another way to avoid water building up in the soil is to add a few small stones or pebbles to the bottom of your pots. This ensures that the drainage holes don’t get blocked by clumps of potting mix.
If you’re using plastic plant pots, then this next tip is for you. Plastic pots hold in every drop of moisture, which means if you accidentally overwater, or the drainage holes get blocked up, there’s nowhere for that water to go and it’ll likely damage your plant and cause yellow leaves (among other issues). Although clay and terracotta pots can be a little bit more expensive and are breakable, their upsides are much more than just the aesthetic. The clay they’re made of is permeable which means that some of the water in the potting mix can evaporate through the sides of the pot.
You tend to buy your plants in plastic pots from nurseries or plant shops as they are much more economical, but this doesn’t mean they are the best tithing for your plant. So sometimes it is worth investing a little more to make sure that the roots of your Watermelon Peperomia are not sitting in too much moisture.
Another cause of yellow leaves on Watermelon Peperomia plants is too much direct sunlight. Although they can tolerate the odd spot of direct light, indirect is what’s best for your Watermelon Peperomia. If the yellow leaves look quite scorched, then it may be because they have been burnt from the sun.
Unfortunately, once the leaves on your Watermelon Peperomia have been burnt by the sun there is no reversing that. Trim off the worst affected yellow leaves and move your plant to a shadier spot, away from any direct sunshine. You need to watch out a little more in summer when the sun is a lot stronger and is out for more of the day whereas in winter you can get away with placing most of your plants a little closer to the window to capitalise on the light if you choose to.
A slightly rarer cause of yellow leaves on your Watermelon Peperomia is a pest infestation. Pests suck on the plant’s leaves, exhausting them and causing them to turn yellow in most cases. Watermelon Peperomia plants are susceptible to scale insects, mealybugs and spider mites.
Whilst an infestation is more common when the plant is struggling due to the wrong environment or care, it can happen to a plant in good health too if you’re unlucky so it’s an important one to rule out if you spot yellow leaves.
Most pests are visible to the human eye so we can catch the problem by properly inspecting the leaves. Check the undersides of the leaves carefully as this is where the unwanted visitors like to hang out! If you spot pests lurking on your plant the first thing to do is isolate your Watermelon Peperomia from all of your other houseplants. Pests can easily jump across plants if the leaves are touching so you want to avoid the insects spreading to any of your other plants..
The next step is to then trim off all badly affected leaves to curb the growth of the infestation. Then give your plant a wash down in the sink or shower and treat with an insecticide or neem oil.
A pest infestation isn’t always a death sentence for your Watermelon Peperomia as long as you have caught the problem early. If you are struggling to stop the infestation after treating with an insecticide, then it may be best to say goodbye to your plant. As much as this isn’t ideal, it prevents the problem from spreading to your other beloved houseplants so is often better in the long run.
As your Watermelon Peperomia matures, it may occasionally lose a lower leaf as a natural sign of ageing. Before dropping the leaf, it can happen that it turns yellow first as it starts to die. This is nothing for you to worry about as long as the rate of yellowing is slow (slower than the rate of new healthy growth).
If you feel the rate of yellowing is increasing, double-check the environment around your Watermelon Peperomia as well as the potting mix as it could be a sign of one of the issues we’ve detailed above. There is no harm in giving the soil and roots a once over to check for signs of root rot and keep an eye on any changes in light or temperature that may be affecting its health.
So those are the most common reasons why your Watermelon Peperomia may be developing yellow leaves. Some problems are easier to diagnose than others, and some easier to fix. So it’s all about keeping a close eye on your plant, monitoring its environment and identifying any potential issues early. As long as the problem hasn’t spread to a large chunk of your Watermelon Peperomia, then you shouldn’t have too many issues solving the problem and preventing any more yellow leaves.
Written by Billy Dawson