Homemade, Environmentally-Friendly Fertilizer

Fertilizer can be expensive and dangerous to the environment if used incorrectly. Over-application of many store-bought fertilizers can cause algal blooms of toxic algae eventually creating dead zones due to oxygen depletion. Also, while manure is an organic, it is not the most smell-friendly option, and if applied closely to ground water sources such as wells, disease causing microbes can enter these drinking water sources. Compared to these, making your own fertilizer is friendly to your budget and the environment while reducing food waste.

For hobbyist and community gardeners, this guide will walk you through nutrients needed for plant growth, followed by methods of making and utilizing your homemade fertilizer.

Supplies

Supplies vary based on what nutrient or soil acidity you are aiming to fertilize your garden with. In steps 1 - 3, you will understand the major and minor nutrients in the following steps, you will be able to see major and minor nutrients required for plant growth followed by how you can implement it into your garden.

While the fertilizer item you plan to use may vary, helpful supplies include:

Gallon bucket with lid
Hand fork to mix dirt and fertilizer with
Canning jar

Step 1: The Main Nutrients

Nitrogen

Coffee grounds
Leaves and/or grass clippings for mulch
Weeds
Gelatin

Phosphorous

Bones

Potassium

Banana peels
Alliums [chives, garlic, onion tops]

Combinations

Green tea (phosphorous and potassium)
Milk (nitrogen, phosphorous, potassium, calcium)
Fish (nitrogen, phosphorous, potassium)
Seaweed (phosphorous, potassium)

Step 2: Other Nutrients

While the three main nutrients are nitrogen, phosphate, and potassium, there are other nutrients present called micronutrients that plants need only in small amounts. These include boron, zinc, manganese, iron, copper, molybdenum, and chlorine. The following foods can supply your homemade fertilizer with these micronutrients:

Egg shells (calcium)
Blackstrap molasses (potassium, calcium, magnesium, iron, sulfur)
Seaweed (magnesium, calcium)
Potato peels (potassium, phosphorous, magnesium)
Epsom salt (magnesium, sulfur)
Dill (iron, magnesium)
Oregano (iron, magnesium)
Parsley (copper, iron, manganese)
Sage

Step 3: Acidity

Why Acidity?

For optimal plant growth, you need to understand which plants require certain soil acidities, and will need to ask a master gardener at a nursery or do some research on your plants ahead of time. For instance, some vegetables like tomatoes grow better in more acidic soil compared to peas that need soil with lower acidity. Below are some foods that can increase the acidity of your soil:

Banana peels
Vinegar

Testing for Acidity

You should also test the pH (acidity) of your soil to determine if it would be a good fit for your desired plants. You can do this by purchasing a test at a gardening store or store section, or doing it at home.

If you want to learn more about DIY soil testing methods, use this link below:

How to Test your Garden Soil (Almanac)

Step 4: Getting the Nutrients In

There are multiple methods to turn these foods into fertilizer. Methods I cover include:

Apply directly
Just add water
Saving your cooking water
Soaking the food in a bucket or jar with water
Making bone meal

Note:

Besides the herbs above, I was unable to find any information on spices use in making homemade fertilizer, so use foods or water with spices at your own risk.

In steps involving applying a water based fertilizer to your garden, avoid overwatering. While more water may seem beneficial, you could drown your plants instead.

Step 5: Apply Directly

This method is great for epsom salts, grass clippings, dead leaves, weeds, and dried foods. For the best results in your garden, do this before planting.

You will want to:

Apply the substance in moderate amounts in your garden to avoid over fertilization
Take the time to mix in the substance

Step 6: Just Add Water

This method works best with other liquids, like blackstrap molasses and vinegar.

Put 2 tablespoons (29.5 mL) of vinegar to a gallon of water
Mix solution thoroughly
Water plants with this solution several times

Note:

The amount of substance you want to fertilize may vary; the above instructions refer to using vinegar. If using blackstrap molasses, the above amount may not be enough so you will want to either add more to the gallon of water or use less water and the same amount of molasses.

Step 7: Saving Your Cooking Water

This can be done with a variety of vegetables and other foods like potatoes.

Once your food is finished cooking in the water, remove the food
Let water cool
Apply the water to your garden

Step 8: Making "Tea"

This method is similar to using water already cooked with the food. This works with many foods, including potato skins, seaweed, and egg shells.

In a container (bucket, jar), add water and your food of choice
Let your food item soak completely submerged and covered for 1-4 weeks
After soaking period, remove and dispose of the food item
Apply water around plant roots (around the stem)

Step 9: Bone Meal

If bones are a common ingredient in your household, you can make fertilizer with bone meal.

For this method, you will need

Pressure cooker
Spoonful of vinegar
Dash of salt
Food processor or strong finger
Oven or dehydrator

Boil or pressure cook your bones with a spoonful of vinegar and dash of salt until they are soft
Bones are softened enough when you can mush it with your fingers
Transfer softened bones into a food processor or strong blender and blend the bones
With an oven or dehydrator, dry out the blended bones at a low temperature over several hours
Wait until cooled and completely dried until applying to your garden.