DIY Natural Fertilizers: Homemade Solutions for Nourishing Your Plants

Imagine stepping into a world where the food you eat is tailored specifically for you, packed with exactly what you need to thrive. 

That's the world you create for your plants when you use natural fertilizers. 

In nature, plants rely on a complex ecosystem to thrive. They’re nurtured by decomposing plant matter, symbiotic relationships with fungi and bacteria, and the natural cycling of organic matter. But in our gardens - closed environments that don’t necessarily provide the essential ingredients our plants need - we have to recreate this balanced diet.

Enter the art of DIY natural fertilizers. By learning to create your own fertilizers from simple materials like vegetable scraps or coffee grounds, not only are you giving your plants the sustenance they need, but you’re also embracing an eco-friendly practice that respects the circle of life in your garden.

Natural choices

Why do we recommend natural fertilizers? For one thing, they’re extremely plant-friendly. Natural fertilizers release nutrients more slowly than synthetic products like ammonium nitrate, superphosphate, or urea. That means your plants are less likely to be overfertilized or “burned.” 

And as we mentioned, natural fertilizers are good for the environment. They’re made from renewable resources, and they improve soil structure and increase its ability to hold water and nutrients. Natural fertilizers also support the presence of beneficial microorganisms in the soil, which in turn, contribute to the decomposition of organic matter and the natural soil nutrient cycle.

What counts as fertilizer?

Essentially, any substance that provides nutrients for plants could be considered fertilizer. But to give your plants the balanced diet they need, the fertilizer you provide should, at the very minimum, provide nitrogen, phosphorus, and potassium.

Nitrogen promotes stem, leaf, and vegetable growth, and plants need it for photosynthesis, their process of creating energy. 

Phosphorus plays a crucial role in flower and fruit formation, and it supports plants’ root development. It also contributes to seed germination and fosters overall plant vigor. 

Potassium contributes to overall plant health and the ability to resist disease. It helps plants produce and move sugars and starches, and it contributes to strong, thick stems. Potassium also supports water uptake, making plants more resistant to drought conditions. 

Along with nitrogen, phosphorus, and potassium, plants need smaller amounts of calcium, magnesium, sulfur, iron, and zinc to grow and thrive. By mixing up your own fertilizers, you can provide all these nutrients.

Ready to try making fertilizer yourself? Here are some recipes to get you started.

Compost

While compost generally is thought of as a soil amendment — something we add to improve soil structure and enhance microbial life — compost can also be considered a fertilizer. That’s because it adds the important plant nutrients we just discussed to soil.

Make it: Gradually create a compost pile with a generous supply of “brown” ingredients like logs (best placed on the bottom), twigs, newspaper, and cardboard. Add a smaller portion of “green” ingredients like fruit and vegetable scraps, used coffee grounds, tea bags, and fresh grass clippings. Store your compost pile in a sealed container to keep pests out and odors in. Soak your pile every two to three weeks and break it up with a shovel. After two to 12 months, the compost will be dark, crumbly, and smell more earthy than like garbage, meaning it’s ready for you to apply to your garden soil.

Compost tea

Compost tea is a nutrient-rich liquid made by steeping compost in water. The liquid form allows nutrients to be more readily absorbed by the plants' roots or leaves. Plus, brewing compost in water multiplies the beneficial bacteria and fungi in compost.

Make it: Place a couple of shovelfuls of well-rotted compost into a pillowcase or burlap sack. Tie it off to make a large "tea bag." Place the sack in a five-gallon bucket filled with water (ideally, rainwater or dechlorinated tap water). Let the mixture steep for 24 to 36 hours. (Don’t let the compost tea brew for too long or you risk the formation of harmful anaerobic bacteria.) Stir the tea with a stick or large spoon several times a day to introduce oxygen. After brewing, remove the sack from the bucket and let the compost tea settle. From there, water your garden soil with the tea or strain the tea and spray it onto your plants’ leaves. Apply the compost tea every two to four weeks during the growing season for best results.

Use compost tea on edible plants with caution; stop applying it at least two to three weeks before harvesting.

Eggshell fertilizer

Think of eggshells as a “supplemental” fertilizer and a great way to give your plants a healthy dose of calcium. 

Make it: After using their contents, put your eggshells out under the sun to kill potential pathogens. Then, crush the shells and sprinkle them on your soil.

Coffee grounds

Used coffee grounds are packed with nitrogen and fantastic for plants that need acidic soil, including blueberries, cucumbers, and potatoes. Like eggshells, the coffee grounds should be considered a fertilizer supplement.

Make it: Collect your used coffee grounds and spread them lightly over your garden soil every few months.

Banana peel fertilizer

Banana peels, another fertilizer supplement, are a treasure trove of nutrients, particularly potassium. 

Make it: Start by saving your banana peels and drying them out. You can lay them out in the sun or put them in an oven on the lowest setting until they are brittle. Once dried, grind the peels into a powder using a blender or food processor.

To use the banana peel fertilizer, you can mix the banana peel powder directly into the soil at the base of your plants. Or steep the powder in water for a few days to make a tea. Apply banana peel monthly to give a potassium boost to your garden plants.

Safety notes about using organic materials and food waste as fertilizer

• Always ensure that any organic material added to your garden is fully composted to prevent the attraction of pests and the spread of disease.

• Take time to bury or mix the material well into the soil to prevent attracting pests. 

• When growing edible plants, stop fertilizer applications at least two to three weeks before harvesting.