If you’re an attentive plant parent, you might notice tiny white balls dotting the soil surface. In most cases, these balls will not harm your plant. In most cases, they are either perlite or fungi, which can benefit your soil.
A fungal infestation might not sound like a good thing. But before you grab the fungicide, keep reading. Having a fungus among us could give your plant new life!
What Are the Tiny White Balls in Soil? 3 Culprits
Before you can assess if and how you need to treat the soil, you need to identify what the tiny white balls actually are. They will most likely be one of three things: insect eggs, perlite, or fungi.
1.) Insect Eggs
Several critters enjoy laying eggs in moist soil. But for the most part, you won’t be able to see insect eggs with the naked eye. Moreover, fungi will typically have a fuzzy exterior. On the other hand, the eggs of insects will be relatively smooth and gelatinous.
If you’re still unsure, use a knife to slide one of the balls in half. A fungus will contain spores.
Perlite is a common ingredient in potting soil that improves soil drainage and aeration. Made from volcanic glass, perlite balls do not break down.
So it’s pretty easy to tell if the tiny white beads in your soil are perlite. Roll a few between your fingers. Perlite will be hard. Fungi or insect eggs will be squishy.
If you still have the bag of potting mix, you can also check the label. You will likely see perlite listed as an ingredient. If the label does not list perlite, this might indicate that the balls are something else.
If they’re neither perlite nor insect eggs, then the tiny white balls are probably one of two kinds of soil-dwelling fungus: puffball or stinkhorn.
The puffball fungus looks just as it sounds. It starts as a small, white ball that can eventually grow over a foot in diameter!
Young stinkhorn fungi also look like tiny white balls. But, as stinkhorn mushrooms grow, they develop an oblong shape and a foul smell.
What Causes Fungus in Soil
A fungus is a eukaryotic organism that feeds on organic matter and produces spores. The fungus kingdom includes mushrooms, molds, yeasts, mildews, and even rusts.
Fungi can grow in many conditions. But they particularly thrive in warm, moist, and dark environments. (Think of how many toadstools you would encounter while walking through a woodland forest.)
Because they consume organic material to survive, you’ll often find them in places with high amounts of dead leaves, food waste, manure, debris, or other composting items.
You might find fungi growing in soil any time of year. But they’re especially present during periods of high humidity, such as late summer and early autumn.
Puffball and stinkhorn fungi are mostly harmless to gardens. And some fungal activity in soil is beneficial to plants. For example, Fungi break down organic matter, making more nutrients available to plants.
Neither fungus is poisonous to humans. However, puffball fungi look very similar to the young version of the deadly death cap mushroom. So unless you’re a mushroom expert, you should probably avoid munching on these fungi.
Humans will likely avoid stinkhorn mushrooms thanks to their rotting smell. But such a scent will only encourage curious pups. In addition, stinkhorn fungi may cause issues if ingested by small dogs.
A fungal infestation can indicate that your plant is facing other issues, particularly overwatering. Overwatering saturates the soil, preventing roots from getting the oxygen they need to grow. It can also lead to many other problems, such as root rot.
How To Get Rid Of White Fungus in Soil: Step-by-Step Guide
If you notice tiny white fungus balls in soil, don’t panic. Instead, assess the culprit before getting your hands dirty, so to speak. Once you’re sure you’re looking at a fungal infestation, you can get rid of white fungus balls by following these steps.
Just remember: moderate fungal growth can benefit soil health. This applies to houseplants as well as outdoor plants.
Repotting or transplanting plants is time-consuming for you and stressful for the plant. It’s probably not worth risking your plant’s health in the attempt to remove mini mushrooms.
1.) Remove Fungi by Hand
Yep. If you catch the fungi early on, the easiest way to eradicate them is to remove them by hand. Pluck each fungus from the topsoil and dispose of them in your compost bin.
Ideally, you also want to identify the mycelium.
A mycelium is the fungal root system from which the fruiting bodies grow. It looks like a network of white, branching threads.
If you wear a pair of gloves to complete this chore, remember to wash the gloves afterward to prevent spreading the spores. (Same goes for any spades or other garden equipment you use.)
2.) Get Rid Of Excess Organic Matter
While removing the fungi, you should also remove excess organic matter. Fungi thrive on decomposing debris such as grass clippings, leaves, branches, and manure. Organic material is anything that contains carbon compounds formed by living organisms (plants and animals).
By clearing this debris, you are removing the fungi’s food source. And without food, the fungi will eventually die.
That said, some organic content is necessary for your plant to survive. So removing all organic matter from the soil is difficult and impractical.
3.) Let the Soil Dry
Overwatering is a common cause of fungal infestation as fungi thrive in moist environments.
As soon as you notice a fungal infection, stop watering your potted plants. Fungi can neither grow nor reproduce in dry soil, so let the soil dry out completely.
It’s difficult to control whether or not your outdoor garden beds receive rainwater. But you can adjust downspouts and other architecture that could lead to excess water reaching your soil.
4.) Change How You Water the Plant
It’s worth repeating: overwatering plants can cause more trouble than under-watering plants. This tip is especially true for houseplants and succulents.
You want to let the topsoil dry out between watering most potted plants.
Bottom watering is another strategy you can use for potted plants. Rather than apply water to the topsoil, place water in the saucer where the pot sits. Plants will use capillary movement to soak up the water they need. (Once the top of the soil feels moist, remove excess water from the saucer.)
You can theoretically use bottom watering for garden beds. But this method would require implementing a complex irrigation system.
5.) Use a Fungicide
If the problem persists, it might be time to apply a fungicide to your soil. A fungicide is a pesticide that kills fungi and their spores. Some fungicides also prevent the growth of future fungi.
The word “fungicide” might conjure notions of toxic chemicals. But there are many organic fungicides available to gardeners. (Check out the next section for natural fungi soil treatments.)
6.) Replace Infected Soil
When the fungal infection has spread throughout the soil, replace the infected soil with a fresh potting mix. This step is a worst-case scenario option. However, following the above steps will be enough to remove the fungi in most situations.
If the infected plant lives in a pot or container, soil replacement is straightforward. Rest the pot on its side. Use a knife to loosen the soil from the pot’s edge. And then gently wiggle the plant out of the pot.
In cases of severe infection, rinse the roots with a diluted solution of warm soapy water. Next, wash the pot with warm soapy water as well (helps prevent mold on plant pots). Then, re-plant the plant in the cleaned pot using fresh potting soil.
Identifying where the infection stops in flower beds or communal containers can be tricky. So it’s useful to catch the infestation early.
But, once you have determined a perimeter, follow these same steps for soil replacement.
Place the infected soil in a compost bin. If you would like to reuse the infected soil, you will need to dry and sterilize it first.
Natural Fungi Soil Treatments
Using a diluted solution of Neem Oil is a popular organic treatment for plant pests and fungi.
But many common household products will also do the job. To make a simple spray, mix any of the following ingredients. Using warm water will help powders dissolve faster.
- Baking Soda: 2 Tbsp of Baking Soda to 1 Gallon of Water
- Dish Soap: 4 Tsp of Soap to 1 Gallon of Water
- Cinnamon Essential Oil: 10-15 Drops of Cinnamon Oil to 1 Cup of Water
- Vinegar: 1 Tbsp of Vinegar to 1 Gallon of Water
Spray these solutions directly onto the soil (avoid spraying the foliage). For stubborn fungi, increase the dosage slowly.
If you are using dishwashing soap, make sure it does not contain bleach, degreaser, or any other additive that could potentially harm your plants.
You can use cinnamon powder instead of cinnamon essential oil. However, sprinkling the powder onto the topsoil will yield limited results.
Another option is to use garlic. But this method requires a bit more work without yielding better results.
To make this fragrant fungicide, begin by peeling an entire head of garlic. Next, chop the cloves as finely as possible, mixing with a cup of water; use a blender or food processor for best results.
Add another three cups of water and two tablespoons of liquid soap. Let this mixture steep for at least 12 hours. Then, strain the mixture to remove the garlic bits. Refrigerate the garlicky fungicide between uses.
Are White Fungus Balls in Soil Harmful to Pets?
Yes, they are. While safe for humans, most mushrooms are toxic to animals. If your pet ingests them, it may experience vomiting, diarrhea, dehydration, and stomach pain.
If you suspect your pet has eaten mushrooms, immediately contact the vet and keep a sample for identification. Protect your pets from white fungus balls and mushrooms to avoid potential health risks.
What Caused the White Fungus in my Soil?
Fungi are naturally attracted to a soil that is rich in nutrients and organic matter that is in the process of decaying. However, if the growing conditions are excessively warm and humid, your plants may be at risk of developing fungal growth, particularly if you overwater them.
Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.