Monsteras have become popular houseplants, and it’s not difficult to see why. They add a tropical vibe to any room or office and are incredibly easy to grow. Their signature fenestrated leaves aren’t only aesthetically pleasing, but they help purify room air as well.
But what happens when these leaves start to look weak and sick? What if you find brown spots over them? Unfortunately, Monsteras are prone to root rot; a fungal infection caused by overwatering.
Even though the word “root rot” strikes fear into plant lovers, it’s not always challenging to treat. There are various ways to treat Monstera root rot. In addition, there are some preventive measures to prevent this issue.
In this article, we’ll walk you through everything you need to know about Monstera root rot. From its causes and treatment to preventive measures. So let’s get started.
Root rot is a fungal infection that develops in plants growing in wet or moist soil. The disease begins under the soil surface and then moves up the stem, then the leaves. Since it begins beneath the soil, even experienced gardeners can miss the signs of this disease until it progresses.
The roots change their color from white to black or brown. During rotting, the roots’ environment is favorable for bacteria and fungi to thrive. As a result, roots become mushy and brown. If you don’t treat root rot, it can eventually kill your plant.
Plants, like us, need oxygen to thrive and grow. What happens in root rot is that overwatering or poor drainage inhibits the roots from absorbing all the oxygen they need to survive. When roots are oxygen deprived, they start to decay, spreading the infection to healthy roots as well.
One more reason for root rot is soil fungus. Weak roots are susceptible to fungal infection. When the soil becomes overly wet, dormant spores can become active again and infect the roots. Here are some of the factors that contribute to root rot in Monstera:
You’ve probably heard about the significance of choosing the right pot size for your plants. Here’s why, if you plant your Monstera in a pot that’s too large, some soil areas won’t have enough root hairs to absorb moisture. Accordingly, areas with no roots remain moist for extended periods, until the water evaporates or drains. That way, the soil retains more water, which eventually causes root rot.
Similarly, if your pot doesn’t have enough drainage holes, excess water won’t drain. Which leads to wet damp soil that’s prone to rotting.
Clay soil retains water for a longer time and becomes compact when wet.
If you plant your Monsteras in clay soil or soil containing too much organic matter, the water won’t drain properly. This leads to extra moisture, which causes root rot eventually.
Overwatering is one of the most common causes of root rot in Monsteras. When you water your Monstera too frequently, you don’t let the soil drain between waterings.
Consequently, roots become susceptible to rotting. In general, the soil’s top layer should be dry before watering your plant.
Some fungi like Pythium, Fusarium, Rhizoctonia, and Phytophthora thrive in damp and moist conditions. These fungi might be present in your plant’s soil, but they only become active when you overwater your plant.
In addition, insects can transfer microbes from these fungi to other parts of your plant.
It’s no secret that fertilizers are beneficial to plants. Though, over-fertilization leads to root shrinkage, making it difficult for roots to absorb water from the surrounding soil. When this happens frequently, your soil ends up in a damp condition, which further leads to root rot.
Fertilizers that contain high nitrogen levels also increase the risk of root rot as they lead to root shrinkage.
Now that you know what causes root rot, it’s time to understand how to identify it. It can be challenging to diagnose root rot at its early stages.
However, there are some telltale signs to look for if you suspect you’re overwatering your plants.
One of the sure signs of root rot is black spots on the leaves. Black spots mean pathogens and bacteria have spread across your plant and affected the leaves.
You may also notice a yellow hue around the dark lesions.
Monsteras, like most plants, should grow and thrive in their growing season. If you notice your plant isn’t growing as expected, then there’s a problem.
This isn’t a sure sign of root rot, but in many cases, root problems are the main cause of stunted growth.
The state of the foliage is a clear indicator of your plant’s overall health.
If your Monstera leaves are turning yellow or brown, you’re most likely dealing with root rot.
Wilted leaves might be a sign that your plant isn’t getting enough water from the soil. In that case, you need to inspect the soil to determine whether it’s dry or wet. If it’s dry, you might need to add some water.
Conversely, if the soil is damp, that means the roots can’t draw in enough moisture. At this point, you need to check your Monstera’s roots for signs of rotting.
If you smell a foul odor coming from your Monstera, the roots are likely decaying. To check, you can gently pull them from the soil and inspect them.
Healthy roots should be white, like in most plants. If the roots are smelly, black, or weakened, then it’s a clear sign that your plant has root rot. Rotten roots often feel soft, mushy, or crumbly. They also have a sulfur-like or rotting matter smell.
Monstera root rot is a serious problem that will kill your plant if you don’t treat it. It’s also worth noting that the faster you diagnose and treat root rot, the more likely your plant will recover.
The recovery process starts with removing the damaged parts, then repotting the plant. After that, you should place the plant somewhere to dry out and avoid overwatering in the future.
If you’re planning to repot your plant in the same pot, you should disinfect it using a bleach solution. How?
Start by taking the plant out of the pot. Then, cover the roots with a plastic bag. After that, use a bleach solution to disinfect the pot, then wash it with warm water.
This part is critical to avoid further infections. Using a sterile knife or scissors, cut down all the infected roots and unhealthy tissues.
After you remove the damaged roots, place the remaining ones in the sun for a few hours to dry. Then, you can use a fungicide or hydrogen peroxide to ensure the roots are sterile.
Now your Monstera should be ready for repotting. You may use the old soil after you disinfect it with vinegar. However, we recommend repotting in fresh soil to avoid the risk of reinfection. You also need to ensure the new soil has proper drainage.
To do this, add perlite or sand to the soil mix. After you make sure the new soil has adequate drainage, fill 1/3 or 1/2 of the new pot with potting mix.
Just like getting rid of infected roots and stems, pruning back the damaged leaves is also essential. Why?
Because your Monstera now has fewer roots, which won’t be able to carry much foliage. Therefore, you should prune back ⅓ or ½ of the leaves to allow your Monstera to recover better.
Monstera root rot is a serious and common problem that requires early treatment. That’s why we recommend you take a few precautions while taking care of your plant.
First, you need to avoid overwatering, as this is the main reason for root rot. In addition, you should regularly inspect your plant’s roots, stems, and leaves for any signs of infection.
Finally, make sure your plant gets enough indirect sunlight daily, it’s essential for its growth and overall health.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.