Peperomias are popular houseplants whose beautiful leaves can brighten up any interior space.
One of the most common problems encountered by Peperomia owners is the presence of brown spots on their plant’s foliage, which can greatly affect the overall aesthetic of the plant.
The most common causes of brown spots on a Peperomia are too much light, underwatering, overwatering, using the wrong kind of water, pests, diseases, temperature changes, humidity problems and fertilizer problems.
In this article, we will discuss more about each of these causes and how to remedy each one. So, if you are having the same problem and wish to learn more about it, just keep reading.
Identifying brown spots on Peperomias
The brown spots that indicate problems in a Peperomia do not have a uniform look. There are those that take up most of the leaf, while others are just tiny dots on the leaves’ surface.
The spots can appear on leaves that have gone soft and mushy, or on crispy and dry leaves.
The brown spots can also appear inflamed or raised on the surface of the leaves.
The spots can also appear on the stems of the plant, although they are most commonly observed on the leaves.
Furthermore, if you do not see brown spots on the tops of the leaves, there may still be some present on the undersides.
Why are there brown spots on my Peperomia?
Too much light
Peperomias’ natural habitat is tropical rainforests. They grow on rotten wood or on the trunks of other trees and the only sunlight they get is that which penetrates the thick treetop canopy in the forest.
This dispersed light, then, is what Peperomia plants prefer when they are kept as houseplants.
If your Peperomia is grown outdoors or if it is placed near a window that lets in too much light, this can lead to its leaves getting scorched and the tips of the leaves will turn brown from sun damage.
Remedy
If too much sun exposure is what is causing brown spots on your Peperomia, you will need to transfer it to a different spot where it will only get indirect light.
If you keep the plant near a window, make sure that it is not a south-facing one because these windows generally let in too much light. If the only available window in your home is south-facing, you can try to diffuse the light by placing a sheer curtain over it.
Underwatering
Another cause of brown spots on Peperomia plants is when the plant does not get enough water.
The brown spots in this case are usually dried leaf-tips, and the leaves may also be drooping.
You can check whether your plant is underwatered by feeling the soil in the pot. Stick your finger about two inches deep into the soil. If the soil is dry at this depth, it means that the plant is probably not getting as much water as it needs.
Remedy
To fix this problem, water your plant immediately until you can see excess water dripping through the drainage holes at the bottom of the pot.
In order to prevent underwatering your Peperomia in future, you need to be vigilant about its watering needs. Water it when the top inch of soil in the pot is dry to the touch, and never let the soil dry out beyond that.
Overwatering
If your plant gets more water than it needs, it can also lead to brown spots on the leaves. Overwatering can arise from giving the plant too much water every time you water it, watering it more frequently than you should, or not adjusting the watering schedule when the seasons change.
The cause of brown spots on an overwatered Peperomia is edema, which is a physiological occurrence caused by the plant taking in water faster than it can use it or get rid of.
Because of the water buildup, the pressure in the leaf tissue is increased. This causes the cells to rupture and brown spots are the result.
Another problem that stems from overwatering is root rot. This is a condition caused by the plant’s roots constantly standing in waterlogged soil, which eventually drowns them. The dead roots become susceptible to opportunistic pathogens, making the rot spread more aggressively to the rest of the plant until it eventually succumbs to the disease.
Remedy
The first thing you need to do if you suspect overwatering is to stop watering the plant immediately and allow the soil to dry out.
If you think your plant has root rot, you may also need to repot it.
To do this, remove the plant from its pot and wash off as much of the old potting soil as possible from the roots. Inspect the roots for sections that are brown or black; these are rotten and will need to be removed. Use a sterile knife to cut off the rotten roots until only the white, healthy roots remain.
Prepare a new pot that has drainage holes at the bottom and fill it with fresh potting soil. Place the plant in the middle of the pot and cover the roots with more soil.
Do not water the plant immediately, as the fresh potting soil should already be a bit moist.
You will know when you next need to water the plant by feeling the soil: if the top two inches of soil are dry, water the plant.
Adjust the volume and the frequency of watering according to the climate where you live, the season of the year and the current weather conditions.
Using the wrong water
Another reason your plant has brown spots could be that you are using water that your plant does not like.
As we mentioned, this plant is native to tropical rainforests where there is abundant rainwater, and rainwater does not have a high mineral content like tap water does.
Peperomia plants are sensitive to the fluoride and chlorine in tap water, and if these minerals accumulate in the soil over time, it can lead to root burn which may present as brown spots on the plant’s foliage.
Remedy
The best and most affordable water to give your Peperomia is rainwater, but if you do not have access to rainwater, you can use purified or distilled water instead.
If you have no other choice but tap water, pour the water into a container and let it sit for 24 hours before using it to water the plant. This will give the fluoride and chlorine time to evaporate, and the water can then be used safely on your Peperomia and other houseplants.
Pests
Brown spots can also be caused by pests, and one of the most commonly observed pests on Peperomias is the spider mite.
This bug spins sticky webs all over your plant, and these are the tell-tale signs that you are dealing with this particular pest.
Spider mites pierce the plant’s leaves to suck the sap from them, and it is these bite marks that then become brown spots.
Remedy
The first step when treating a Peperomia for pests is to make sure you have quarantined it in a part of the house that is nowhere near your other plants, so that the infestation does not spread.
You can get rid of spider mites by washing the leaves with a steady stream of water that is strong enough to dislodge the pests.
Alternatively, you can just use a commercially available pesticide, which is effective but may not be a great option for those who do not like using chemical sprays for safety reasons.
Placing the plant under a running shower to simulate rainfall can also help wash away these bugs.
If you were able to catch the infestation in its early stages, you can simply wipe the spider mites off with a damp cloth.
Spraying rubbing alcohol directly on the mites can also be effective in killing them.
Or, if you have neem oil at home, mix two tablespoons of this oil into a spray bottle of water, and spray the mites with the solution.
Whichever method you use, make sure you repeat the process once a week until all of the spider mites have been eradicated.
Disease
Disease can also be a cause of brown spots on your Peperomia. There are many diseases that can afflict the plant, and the sooner you can determine which one it is, the faster you will be able to treat it.
Peperomia diseases that cause brown spots include the following:
– Peperomia ringspot virus.
– A fungus known as Rhizoctonia leaf spot, which leaves mushy, dark-brown spots all over the plant.
– A fungus that leaves brown circles on the leaves is Phyllosticta leaf spot.
– Cercospora leaf spot is a fungus that causes raised brown or black spots on the underside of the leaves.
Remedy
If you suspect a disease to be the cause of the brown spots on your Peperomia plant, remove the infected leaves and stems using a sterile pair of scissors.
Make sure you dispose of these leaves properly so that they do not infect other plants.
Also ensure that all the plant’s healthy leaves are dry to discourage any further growth of fungi.
If you have a neem oil solution, spray the bottom of the leaves.
If it appears that every leaf on the plant is infected, you might be better off disposing of the entire plant and starting anew.
If you suspect a viral infection, you will unfortunately have to destroy the plant because there is no cure for viral diseases in Peperomias.
Temperature changes
Brown tips on the Peperomia’s leaves can be due to sudden temperature changes.
It could be that the interior of your home is too hot, or the plant is positioned too close to a heater or a radiator. The high temperatures will dry out the plant’s leaves very quickly, which is why they will turn brown.
Likewise, if you keep your Peperomia outdoors during the cold winters, or under air conditioners or in other spots in the house where it can get hit by cold drafts, this will also cause its leaves to turn brown.
Remedy
Whether the room where you keep your plant is too cold or too hot, the remedy is the same: move the plant to an area where the temperature is between 65 and 80 degrees Fahrenheit.
If the plant is exposed to temperatures lower than 65 degrees or higher than 80 degrees for extended periods of time, it will experience temperature stress which is best avoided.
Make sure you keep the plant away from heaters, radiators, air conditioners and windows or doors that may let in cold drafts through their cracks.
Humidity problems
The Peperomia’s natural habitat is humid, so if you are keeping your plant somewhere that is too dry for it, its leaves will dry out and turn brown.
Peperomias generally do not need very high humidity, but this also depends on the species of Peperomia you have. Usually, the thicker the leaves of the Peperomia plant, the less sensitive it is to low humidity.
Remedy
If you live in a dry region, you might need to boost the humidity for your Peperomia.
The simplest way to provide humidity for the plant is to place it in a humid room in the house, such as the bathroom or the kitchen.
You can also mist the plant’s leaves once in a while to moisten them, or you can use a pebble tray. Place the pebble tray, filled with water, under the plant’s pot and as the water from the tray evaporates, it will moisten the leaves and the soil in the pot.
If you have other plants that enjoy a little humidity, place them close to the Peperomia so that they create a microclimate around each other.
Finally, if you have the means, you can also buy a humidifier to automatically regulate the humidity in your home.
Fertilizer problems
Peperomias do not really need to be fertilized. As long as the soil in their pot is rich enough, they will grow well. You can fertilize your plant if you want to give it a boost, but if you do this too much and too often, it can lead to a buildup of nutrients in the soil which can be toxic to the plant. Its roots will get root burn and this can also lead to the browning of its leaves.
Remedy
To fix a Peperomia that has been overfertilized, flush the soil with water to get rid of some of the nutrient buildup.
A Peperomia only ever needs to be fertilized three times a year at the most. You might need to dilute the concentration of the fertilizer compared with the package instructions.
Only fertilize the plant in its growing season, because this is when it will use the most nutrients from the soil.
You can also use organic fertilizer to lessen the possibility of root burn from mineral toxicity.
Conclusion
The Peperomia is one of the most popular houseplants because of its beautiful leaves and minimal care requirements.
One of the most common problems encountered by Peperomia owners is brown spots on the leaves and stems of the plant.
The most common causes of brown spots on Peperomia plants are too much light, underwatering, overwatering, using the wrong kind of water, pests, diseases, temperature changes, humidity problems and fertilizer problems.
Image: istockphoto.com / Muhammad Rayhan Haripriatna