How to Make a Powerful Homemade Potato-Based Liquid Fertilizer
Creating your own liquid fertilizer at home is a fantastic way to enrich your garden naturally, boost microbial activity in the soil, and provide essential nutrients to your plants. One of the simplest and most effective fertilizers you can make uses a humble ingredient: potatoes. Potatoes are rich in carbohydrates and nutrients, making them an excellent base for a nutrient-dense, microbe-friendly fertilizer.
This potato-based liquid fertilizer is easy to prepare, affordable, and incredibly effective for promoting strong, healthy plant growth. Here’s how you can make it step-by-step.
Ingredients and Tools You’ll Need:
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4 to 5 medium-sized potatoes (cleaned)
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1 tablespoon of sea salt (not table salt)
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An equal amount of compost (as the amount of potatoes used)
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Cheesecloth or breathable fabric
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A small stone or other weight
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10 liters of non-chlorinated water (rainwater is best)
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A large container with a loose-fitting lid
Step 1: Prepare the Potatoes
Start by washing the potatoes thoroughly to remove any dirt. There’s no need to peel them. Next, grind or grate the potatoes. You can use a hand grater, a food processor, or any tool that helps break the potatoes into small pieces. This step is important because it increases the surface area and helps release the nutrients and carbohydrates inside the potatoes, which will feed the microbial life during fermentation.
Step 2: Add Sea Salt and Compost
Mix the grated potatoes with one tablespoon of sea salt. Sea salt provides trace minerals that are essential for plant health and supports the breakdown of the potato mixture. Avoid using regular table salt, which may contain additives that could harm your plants.
Then, add an equal amount of compost to the mixture. Compost brings in beneficial microorganisms and additional nutrients, enhancing the microbial richness of your final fertilizer. This combination of potato, salt, and compost creates a perfect environment for microbial fermentation.
Step 3: Wrap the Mixture
Place the potato, salt, and compost mixture into a cheesecloth or any breathable fabric. Tie it securely to form a pouch. Add a small stone or other clean weight into the pouch to ensure it remains submerged in the water later on. This setup allows nutrients to diffuse into the water while keeping solids contained.
Step 4: Prepare the Water
Use about 10 liters of non-chlorinated water. Chlorine in tap water can kill beneficial microbes, so it’s best to use rainwater if available. If you must use tap water, let it sit uncovered in an open container for 24–48 hours to allow the chlorine to evaporate.
Step 5: Soak and Ferment
Place the pouch into your container filled with the prepared water. Make sure the container is large enough so the pouch can move freely within the water. Close the container with a lid, but don’t seal it tightly. Fermentation releases gases, and a tightly sealed lid could cause pressure to build up. A loose-fitting lid allows the mixture to breathe while protecting it from contaminants.
Set the container in a partially shaded area. Avoid direct sunlight, as it can overheat the mixture and negatively affect microbial growth. Let the mixture ferment for about one week.
Step 6: Remove the Pouch and Dilute
After a week, remove the pouch from the container. The liquid inside should now be darker and have a slightly earthy or fermented smell—signs that nutrients and microbial life have been successfully developed.
Before using the liquid fertilizer, it’s important to dilute it. The mixture is concentrated, and applying it directly can be too strong for plants. Use a ratio of 1 part fertilizer to 10 parts water. For instance, if you have one cup of fertilizer, mix it with 10 cups of water before application.
Step 7: Apply to Your Garden
You can apply the diluted fertilizer directly to the soil around the base of your plants. It’s suitable for all types of plants—vegetables, flowers, herbs, and even indoor plants. This fertilizer nourishes the soil, strengthens root systems, and promotes vibrant, healthy growth.
Apply it once a week or whenever your plants need a nutrient boost.
Final Thoughts
This potato-based liquid fertilizer is not only easy and inexpensive to make, but it also supports a healthy garden ecosystem. By combining simple kitchen scraps and compost with the right fermentation process, you’re creating a rich, living solution that feeds both your soil and your plants. Give this natural fertilizer a try and watch your garden thrive like never before.
