How To Make Your Own Dry Fertilizer

I'm sure many of us became new plant parents or decided to grow our own food over the course of quarantine. Taking care of a plant doesn't sound too difficult. All you need is good soil, sunlight, and water. But what do you do if a plant isn't producing many flowers or fruits? There are a lot of reasons this might happen, but one way to help boost your plant's production is by using fertilizer!

Buying fertilizer from the store can be expensive, especially if it's organic or a specialty blend. I'm a gardener who grows about 130 square feet worth of food, so I go through fertilizer pretty quickly. That got me thinking: Can I make my own?

The short answer is yes. It won't be as fortified as what you might get at the store, but you'll get the satisfaction of having made it yourself from locally-sourced ingredients.

Here's what you'll need:

  • A mortar and pestle or some way of grinding/crushing ingredients

  • A jar (I recommend starting with 4 oz.)  to put the finished product in

  • 5 eggshells

  • 4 tablespoons of cayenne pepper

  • 4 tablespoons of coffee grounds

  • A small chunk of charcoal (it should fit in your palm)

Once you have your ingredients ready, set up your workspace. It should be easy to clean and well-ventilated. It may be prudent to wear a mask or respirator if you're sensitive to dust.

Measure the coffee grounds and cayenne into your jar. I recommend putting the lid on after doing this, at least for a few minutes, to let the dust settle. I know I tend to sneeze from the cayenne!

Next, grind your eggshells. I like to grind half of them at a time as it's easier to get a fine powder when there are fewer in my mortar. If you're using a plastic bag and rolling pin or a food processor/blender, you can grind the eggshells all at once. When they're a powder, go ahead and add them to your jar.

The last ingredient is the charcoal, and it tends to be the messiest. Follow the same procedure as you did for the eggshells. If you're using a mortar and pestle, I recommend grinding more slowly than with the eggshells, as the charcoal likes to split and jump out of the bowl. When it's a fine powder, add it to the jar as well.

Now shake it up! Once the mixture is fully combined, you have a homemade, dry fertilizer!

To use your new fertilizer, you can either mix it into the soil before transplanting a new plant or sprinkle it on top of the soil around the base of the plant. When transplanting, be sure to always mix any kind of fertilizer into the soil, homemade or not. Once everything’s situated, add some water! The water will break down the nutrition and make it easier for the plant’s roots to absorb.

Pretty great, right? But what exactly does each of the elements of our fertilizer contribute? Let’s take a look:

  • Eggshells: calcium supplement (calcium carbonate)

  • Coffee Grounds: soil acidifier (magnesium, nitrogen, and potassium)

  • Charcoal: pH control (calcium carbonate and phosphate)

  • Cayenne: natural bug repellant (capsaicin)

The charcoal offsets the higher end of the acidity from the coffee grounds, the coffee grounds add much-needed nitrogen, the eggshells provide extra calcium, and the cayenne helps deter any bugs from munching on your plants!

Now go forth, gardener! Plant some plants and fertilize them to reach their maximum potential!