Introduction.
We’ve learned about correctly fulfilling a houseplant’s basic needs like light, soil, and water and protecting it from external threats like pests. Unfortunately, pests aren’t the only thing to keep an eye out for — there are many other risk factors that are just as dangerous to your plant’s well-being (if not more). A prime example is houseplant Fungus Disease and its spread. It’s essential to know what houseplant fungus diseases are, their common types, and how to keep your plants safe from them.
You’ll be equipped with the basic intellectual arsenal to detect, identify, and treat common houseplant fungus diseases in a timely manner to prevent their spread to other healthy plants.
Tips to Prevent Houseplant Fungus Diseases Growing With Your Houseplants.
It all starts with prevention — because what’s better than the disease not happening in the first place?
You can prevent houseplant fungus diseases by making the conditions as unfavorable for them as possible. While the humidity and temperature preferences vary amongst different fungi types, they mostly show up and thrive in humid conditions with a lack of open airflow.
Considering that, here are a few preventive measures you can take to keep houseplant fungus diseases away from your plants:
- Avoid overwatering by always checking the soil’s moisture level before each watering session. You can check it by inserting your fingers about an inch or two into it and checking for moisture. If it’s there, hold off on the watering can.
- Since limited airflow encourages houseplant fungus disease growth, you should ensure healthy ventilation around the plant and maintain good aeration in your soil. Houseplants shouldn’t be crammed into a single room. Even adding a fan to your indoor houseplant setup can help prevent fungi by stimulating airflow.
- Perform regular drainage checks on all your plants and don’t let them get waterlogged. Since moisture buildup is the mother of fungi, waterlogging is the last thing you need in your houseplants (which is when there’s too much water stuck in the plant’s root zone due to poor drainage).
- Another tip to avoid moisture buildup in your plants is to water them in the morning instead of doing it in the evening or at night. That’s because the sun is a great natural evaporator of the excess water off of the plants and soil, and you’d miss out on that by watering in the dark hours.
- You can also keep spraying your plants with anti-fungal sprays (homemade or store-bought) periodically to prevent houseplant fungus disease outbreaks. A water and baking soda mixture is one of the simplest and most effective DIY sprays you can make. It disrupts the ion balance of fungal cells and prevents spores — but we don’t need to get into all the scientific jazz, all you need to know is that it’s easy and it works!
- Don’t leave dead plants or dropped leaves lying around for too long as they can rot and lead to houseplant fungus disease growth.
Different Houseplant Fungus And Ways to Deal With It.
Sooty Mold | Pretty Bad.
Unlike yellow mushrooms, sooty mold is a fundamental cause of concern. It’s a black fungus that’s a gift from unwanted visitors like aphids, scales, and whiteflies.
These pests secrete clear honeydew, which is where sooty mold grows from. Sooty mold is by no means harmless to your houseplants. It forms a covering on the surface of their leaves and blocks out their exposure to sunlight. As you can imagine, that interferes with photosynthesis — i.e., the bread and butter of your houseplants. As a result, they can suffer from symptoms of stunted growth and decoloration.
Here’s how you can deal with sooty mold:
The first step is to target the source of the problem. In this case, it’s pests (and the honeydew they secrete). Start by identifying the type(s) of pest(s) thriving in your houseplants, and take pest-specific measures to get rid of them as soon as possible. (The previous article has covered all three pests that give rise to sooty mold, including ways to identify and get rid of them.) Wash the affected plant leaves using a hose. But be gentle! You don’t need to give those leaves a pressure wash; just a steady flow of water is generally enough to knock pests off.
Spray a non-toxic pesticide or neem oil all over the leaves of an affected plant, also reaching for cheeky spots (like stem cooks, nodes, and underneath the leaves). It’s advisable to take your indoor plants outdoors for this little activity if you don’t want to stink up your home. You’ll have to repeat this a few times to see noticeable results.
Once you’ve successfully gotten rid of the pests, you’ve successfully addressed the source of the problem! Now, to easily clean off the actual sooty mold — wipe the leaves with some water and dish soap, and that should do the trick.
Powdery Mildew | Bad.
If you ever find a white layer of something that looks like icing sugar or flour at the top of your houseplant’s soil, that’s powdery mildew — and it’s bad news. The problem starts with airborne fungal spores and spreads quickly all over the plant (and eventually to other nearby plants if left untreated).
These houseplant fungus diseases thrive in conditions with a lack of light exposure and poor airflow. It’s seriously dangerous to a plant’s health (and life) since it can cause a plant to drop leaves, weaken, and deform.
Let’s hope your precious plants never encounter it — but if they do, here’s what you need to do:
To make sure that the houseplant fungus diseases don’t spread out to other healthy plants, the first step is to set the affected plant at a safe distance from all other houseplants. Its new spot must be properly ventilated with sufficient light exposure.
Next, cut out all the leaves with powdery mildew. Spray the plant with a fungicide for houseplants (following all instructions mentioned on the label). Regularly wipe the plant’s leaves with soapy water to keep the problem from recurring. This also helps keep insects away.
Lastly, remember to wash your hands right after you’ve handled a plant with houseplant fungus diseases. This is to prevent fungal spores from making their way to your healthy houseplants through channels like your hands or clothes.
White Mold | Okey-ish.
White mold isn’t harmful to your plants (hence the “just fine” tag above), but it’s still a sign that your houseplant might be missing out on some of its needs. If you spot white mold on your plant, it means the plant could have better ventilation, lighting, and moisture control.
On the bright side, it’s not something that weakens or damages the plant. However, in the case of indoor plants, it’s still a cause of concern for you as you don’t want to breathe mold in — do you? Here’s how you can get rid of white mold:
Put a mask on, scoop out, and remove the top layer of affected soil using a trowel. Make sure you get all the visible mold out. If there’s too much mold, it might be worth repotting the plant altogether in fresh, sterile soil.
Sprinkle some cinnamon powder over the soil as it’s a natural fungicide that prevents mold growth! Make sure to optimize the plant’s environment with light, healthy air circulation, and precise watering to keep houseplant fungus disease issues away.
Gray Mold (Botrytis) | Bad.
Unlike white mold, gray mold (or Botrytis) is a real cause of concern for your plant’s well-being. Common symptoms include the flowers, stems, and leaves of the plant developing a grayish tan.
The gray spores of this fungal variation prefer relatively cool temperatures and high humidity. An effective preventive measure would be to make sure your houseplant leaves do not remain wet for a long time after each watering session. You can ensure this by simply watering in the daytime to make sure any excess moisture on the leaves gets quickly evaporated.
Gray mold hits the plant’s old parts the hardest, using a broken leaf or stems as its entry point. However, this one’s a fast spreader and can significantly harm your houseplants if left untreated. So, here’s what you need to do:
Start by isolating the plant to make sure the fungal disease doesn’t make its way to other plants. Cut out all moldy parts of the plant, including leaves and stems. Also, scrape out a layer of the soil if there’s visible mold on it. Discard everything carefully and avoid getting it on your clothes. Wash your hands, tools, and clothes afterward.
Move the plant to a spot with conditions that are unfavorable for gray mold — i.e., somewhere with less humidity, warmer temperature, and good ventilation.
On a cloudy day, take the plant outdoors and spray it with a fungicide while closely following the instructions on it. Bring it back in once it dries up.
Remember that dropped and dead leaves, flowers, and stems are the primary food source of mold — so, keep cleaning up and removing these from your plants regularly. You can also get in the habit of dusting any accidental cuts (or broken stems) on your plant with cinnamon powder to prevent mold buildup.
Fungal Leaf Spots and Rust | Bad.
Spotted leaves are a common symptom in houseplants indicating that something’s wrong, but it could be a lot of things. For instance, it could be overwatering, sunlight damage, mineral deficiencies, bacterial damage, or fungal damage.
Spotted leaves from the fungal disease occur as a result of airborne fungal spores sticking to a wet leaf of your houseplant in warm conditions. It all starts from a tiny bump in the leaf (formed by the spore), which expands into a much larger spot. The problem spreads out and covers the entire leaf if left untreated. It can even spread to the stems and branches.
Fungal leaf spots can be of many different colors depending on the species of fungi that are causing them. Common examples include tan, yellow, black, white, and reddish-brown.
A plant might also have rust spots, which are unique fungal leaf spots that show up as orange-red blisters underneath the leaves, and bumpy, red spots on their surface. It generally causes leaves to warp and drop. However, this variation has a higher chance of occurrence in outdoor plants than indoor ones. Here’s how you can treat fungal leaf spots:
Start by isolating the plant to protect its “neighbors” and place it in a cool, dry place with good air circulation around it. Snip away the spotted leaves and carefully seal them in an airtight back to prevent spread.
Try not to mist or overwater the plant, and don’t leave any residual water sitting on its leaves after. Make sure the plant’s stem and leaves dry out well in bright, indirect light after a watering session.
Take the plant outdoors on a cloudy day to spray it with some fungicide solution. Let it dry out well and bring it back inside and repeat this process several times.
Crown, Stem, and Root Rot | Very Bad.
Crown, Stem, and Root Rot occur due to fungal mycelia that can coexist with your houseplants in their soil. The fungus can very quickly spread out and multiply in the right conditions — which in this case, would be limited air circulation, overwatering, and cool temperatures. Here’s how you can effectively deal with crown, stem, and root rot:
If you can see rot at the stem or anywhere above the soil, cut those sections out and sprinkle the cuts with fungicide powder (or cinnamon powder).
Watch out for overwatering! Try to always check for moisture in the soil before watering and always water your plants in the morning. Also, avoid getting any water on the plant’s leaves or stems. You can also try repotting your plant using fresh soil that’s dry and sterile. While you’re at it, get rid of as much of the old soil as you can from the roots, and remember to sterilize your new pot.
Lastly, these houseplant fungus diseases aren’t easy to fight off. So, if the plant still doesn’t show any signs of recovery, you might want to take some healthy cuttings at the top and try to propagate.
We’ve gone over the essential tips to prevent houseplant fungus diseases in your houseplants, the various types of fungi threats to look out for, and how to treat them. You should do everything you can to prevent houseplant fungus diseases, but if they do occur, it’s important to act quickly. That’s because they can spread like wildfire if left undetected (and hence untreated) for a long enough period.
Luckily, there are a lot of well-researched techniques to help a houseplant that’s suffering from a fungal disease. Still, if all else fails, you can always try propagating some of the plant’s healthy cuttings to give it an all-new shot at life — baby Groot style!
Mushrooms | Not Bad.
It’s not uncommon for mushrooms to pop up out of the soil of houseplants if owners fail to maintain preventive measures. For instance, plants kept in humid, warm, and poorly ventilated rooms are at the highest chance of mushroom growth. It all starts from spores that find their way in through clothes, air, or the soil mix itself — and if the conditions are favorable, they grow and pop out!
The most common variety in the case of houseplants is yellow mushrooms — but luckily, they’re totally harmless to plants. In fact, you actually wouldn’t mind their presence at all since they play a somewhat positive role by breaking down the soil. It’s fine to let them live their life and coexist with your plants. However, many plant owners like to remove them since they have pets and children who could try and swallow them.
If that’s the case with you, or you just have minor OCD and can’t stand mushroom growth in your houseplant soil — here’s what you can do: Pull mushrooms out gently by their stems and carefully throw them away. Try not to shake any more spores out of them into the pot while you’re at it.
Make the conditions drier, colder, and more aerated. Scrap out the top layer of your soil and dispose of it to get rid of any spores that may be lying around. Add a fresh layer of sterile potting mix on top. If the mushroom “problem” persists, re-pot your plant.