NPK Simplified – Backyard Food Growing


What is NPK?

Nitrogen – Phosphorous – Potassium

Most fertilizers and soil amendments show this formula somewhere predominantly on their packaging. This shows the ratio of the three most important plant nutrients.

Potassium has a “K” because of it’s name “Kalium” on the periodic table of elements. These three elements are fundamental to the development of all plants in one way or another. 

A fertilizer with a rating of 4-4-4 would be considered balanced because it provides each of these three nutrients in equal proportions.

Nitrogen is necessary for the growth and maintenance of all proteins. A lack of nitrogen will often result in  stunted growth or a yellowing of the plant starting at the ground and moving up the plant. Nitrogen is also an essential food for soil microorganisms which convert organic matter into nutrient forms that are readily available to plants. 

Phosphorous is essential for photosynthesis, which is the process by which plants convert light energy into food. It’s also needed for the development of flowers, fruit and seeds. 

Potassium helps plants regulate the amount of water in their cells. This is key for structure and strength in the plant’s tissues and is also important for overall health and resistance to disease and pests.

Organic Sources of NPK

Choose a good quality fertilizer that’s intended for the type of food or flowers your are growing. I recommend using organic fertilizers, there are many good ones available such as Gaia Green or Myke Brand Mycorrhiza Growth Supplement.

I also recommend Alaska Fish Fertilizer. This liquid is filled with nutrients and very stinky so don’t get it on yourself, use gloves. The plants in the garden loves it and they will thrive with the addition of it to your feeding and watering.  

The NPK numbers on the organic products will be lower than on synthetic fertilizers. They are not weaker they just are just formulated and listed in a different way.

With a good balance of these nutrients you will set the best stage for a plant to flourish and be very healthy. 

When you are ready to dive in a learn about elements, there are six macronutrients and seven micronutrients required for complete plant health.

Don’t get confused by it all, just buy the product called “Trace Elements” and apply as directed for the plants you have. That will cover all of them and you won’t need to become a scientist to understand it all.

Trace Elements

Nitrogen (N) Phosphorus (P) Potassium (K) Calcium (Ca) Magnesium (Mg)

Sulphur (S)

There are seven micronutrients, required in lesser amounts:

Boron (B) Chlorine (Cl) Copper (Cu) Iron (Fe) Manganese (Mn) Molybdenum (Mo)

Zinc (Zn)