The best garden hacks are the ones that use items you likely already have, and you likely have cinnamon in your pantry right now! Cinnamon is a natural, affordable, safe solution for children and animals. So, is cinnamon a simple solution for getting rid of mold in soil?
Cinnamon can kill mold in the soil—as the natural compounds eugenol and cinnamaldehyde found in cinnamon work as a natural fungicide. These compounds work to disrupt the cell wall and membranes of fungi. You can apply cinnamon as a powder, water spray, or essential oil as an antifungal treatment.
This article will discuss the benefits of using cinnamon in your garden, how to kill mold in your soil, and how to prevent mold.
How Cinnamon Kills Mold in the Soil
A study conducted at Dawson College compared the effects of several common spices. They found that cinnamon was effective at killing microbes in the soil, though garlic was the most effective. Cinnamon, garlic, and cloves all have one specific component that makes them effective at killing mold: Eugenol.
Eugenol is a molecule made of carbon, oxygen, and hydrogen. It is very effective at breaking through the membranes of cells. The eugenol in cinnamon helps keep soil healthy by infiltrating and breaking up mold and harmful bacteria molecules.
Cinnamon also contains cinnamaldehyde which further increases its efficacy as a bio-fungicide.
How To Use Cinnamon To Kill Mold in Your Soil
Before treating mold in your soil, you will need to remove as much of the mold as possible. Often, this means scraping off the top layer of soil, but you may find the mold goes deeper into your ground. In this case, you may need to replace some of your soil. Ensure you do not touch the mold directly, as it can make you ill.
Once you remove the visible mold—you are not in the clear yet. There are still fungi that you cannot see. If left untreated, the mold will quickly return, which is the perfect time to use cinnamon.
There are three options for applying cinnamon to your soil:
Sprinkle Cinnamon on Your Soil
Your first option is to sprinkle a fine layer of cinnamon in the same areas where you removed the mold, enlarging the area by several inches on each side. This method will kill any remaining mold in your soil and help prevent a recurrence. This option is an excellent method for treating small areas of mold infection.
Use a Cinnamon Water Spray
Your second option is to make a cinnamon water spray to apply to the soil, which is the best option if you have a large area to cover, as it will require less cinnamon.
Similar to making tea, making cinnamon water is very simple.
- Boil water in a pan and remove it from the heat.
- Add 1 Tbsp (8.28 g) of ground cinnamon for every cup of water.
- Once it cools, put the cinnamon water in a spray bottle and spritz the affected area of your soil.
Apply Cinnamon Essential Oil
Cinnamon essential oil is more of an anecdotal remedy than the other two. Although scientists have proven that essential oil is an effective fungicide, it has not been studied as thoroughly on the soil. As such, there is no standard for the proper dilution method.
Many people have claimed great success with this method, so it is worth a try if you have the oil handy. Use pure oil to avoid introducing unnecessary chemicals into your garden.
Make Sure To Apply Cinnamon in Dry Weather
Cinnamon does not kill mold overnight. It can take several days and sometimes a few weeks to get the problem under control. Since the cinnamon needs time, you should plan to treat the soil when there is no rain for several days. Remember to sprinkle or respray your soil after rainfall if this is impossible.
Causes of Mold in Soil
Mold grows well in wet places. In soil, these damp patches occur as a result of poor drainage.
Poor water absorption can lead to mold on top of the soil, and pooling around the roots causes mold to grow directly on the roots of your plants.
Soil should have a balance between drainage and water retention that gives plants access to water but does not allow water to pool for extended periods. The texture of the soil determines this balance which is an essential factor in mold growth.
In my other article, you can learn more about soil textures. Soil with high amounts of clay has the worst drainage and is far more susceptible to mold than sandy or silty soil: Do All Soils Have the Same Texture?
Preventing Mold in Soil
If poor drainage is the cause of most of the mold in the soil, it makes sense that improving the drainage of your soil will prevent mold growth. It is best to ensure that your soil texture is suitable and achieves proper drainage.
To explore soil texture in more detail, check out my article: The Ideal Soil Texture for Planting Explained
Add Substrate to Your Soil To Inhibit Mold Growth
Sand is the best substrate for drainage. If your soil is already quite sandy, you do not need to alter it. However, if your soil has a lot of clay, you must amend it to prevent mold from developing.
Other materials you can use to increase the drainage of your soil include:
- Compost or vermicompost is a good option if you want to add additional nutrients to your soil. I’ve written a handy how-to article on how to create vermicompost, and you can find it here to learn how to make vermicompost at home: How To Make Vermicompost from Kitchen Waste
- Mulch is effective for improving drainage long-term but is not a quick fix for water pooling.
- Peat moss is lightweight, which allows for adequate airflow and better drainage.
- Perlite or Vermiculite are volcanic rocks that help aerate the soil to aid drainage. However, they also have good water retention, so use them sparingly around plant roots.
Redirect the Water Flow To Improve Drainage
Water naturally runs downhill, so the lowest areas of the ground are more likely to experience water pooling. Even the best-draining soils may have difficulty absorbing all the water in heavy rainfall. French drains, placed in shallow trenches in areas with poor drainage, redirect excess water to prevent pooling.
This video demonstrates the process of installing your French Drain:
Keep Soil Airy To Avoid Soil Compaction
When soil becomes compacted, it decreases its drainage ability. Most natural compaction caused by rain, animals, or manual tools, only affects the top few inches of the soil.
Use a rake or shovel to disrupt the top few inches of your soil whenever you notice that it takes longer for your soil to dry after rain or watering. Areas with plants make it trickier to do this, but working carefully around plants with deeper roots is fine.
Avoid disrupting the soil around root vegetables such as carrots or onions, as they are very shallow, and you may dig them up unintentionally.
Other Benefits of Cinnamon in Your Garden
Applying cinnamon in your garden can do more than eliminate mold. Using cinnamon in your garden can also:
- Kills Other Fungi: Cinnamon can take care of various fungi beyond the mold. Mildew, yeast, and even mushrooms are examples of fungi that you can combat with cinnamon.
- Repel Insects: In addition to killing mold, adding cinnamon to your soil can also help keep mealybugs, aphids, and gnats at bay. All sorts of fungi can attract gnats, and mold is no exception. When your soil is free of bacteria and fungi, it loses its appeal to many pests.
- Remove Rust: You should look at your gardening tools while using your cinnamon solution—you can also use a cinnamon water spray to get rid of rust!
Treating Mold With Other Spices
If you are out of cinnamon, you can use a few other pantry staples as a substitute. All spices that contain eugenol will be effective at getting rid of mold in your soil. These spices include:
Cinnamon is an effective way to combat mold in your soil. A microbe in cinnamon and other spices called eugenol is responsible for this valuable property.
To apply cinnamon to your soil, you can:
- Sprinkle ground cinnamon
- Spray the soil with cinnamon water
- Apply cinnamon essential oil
To help avoid mold in your soil, you need to ensure that your soil has adequate drainage. You can improve soil drainage by:
- Adding substrate
- Redirecting the flow of water by installing a French Drain
- Keeping the top layer of soil loose