In some of our previous tips, we went over the main macronutrients (link) and micronutrients (link) plants need in order to grow and develop properly. In this tip, we discuss in greater detail the role each macronutrient plays and how you can add these nutrients into your soil using natural products found around your house


  • N, Nitrogen
  • P, Phosphate
  • K, Potassium
  • Mg, Magnesium
  • Ca, Calcium
  • S, Sulphur

The three most commonly discussed macronutrients are N, P, and K. When you purchase fertilizers for your garden, lawn, or potted plants, you’ll always see three different numbers listed on the package. These refer to the percentage of nitrogen, phosphorus, and potassium respectively and are always listed in this order.


Nitrogen stimulates leafy plant growth, including development of proteins, nucleic acid, chlorophyll. This is why most lawn and grass fertilizers have a high nitrogen content. Deficiency in nitrogen causes slow spindly growth as well as yellowing of leaves. Stems may also turn red or purple in colour.

Natural sources of nitrogen you can add to your garden or compost pile include coffee grounds, eggshells, and alfalfa pellets (commonly found in rabbit feed). Another natural source of nitrogen is urine. Dilute it with 10 parts water to 1 part urine before adding it to your garden. There won’t be any residual taste or smell and your plants will love it.


Phosphorus is the second main macronutrient and is good for stimulating root developement and fruit production. It is essential during young/seedling stage. Some signs of phosphorus deficiency include small thin stalks, stunted growth, purple veins, and reduced blooms.

Natural sources of phosphorus can be found in bananas and bone meal. Bone meal can be applied directly into the garden. We recommend chopping up banana peels before adding them to your compost pile rather than adding banana peels directly into the garden.


Potassium is important for overall plant health. It helps in protein synthesis and in the flow of nutrients and water up and down the plant. Potassium strengthens plants against cold, heat, disease, and pests. Deficiencies in potassium often show up as brown scorched patches on leaf tips and margins, especially older leaves.

For a natural source of potassium, collect the ashes from your fireplace and spread that directly in your garden or into your compost pile.


Magnesium is at the core of each chlorophyll molecule, and therefore represents an integral component of a healthy garden and healthy plants. Magnesium deficiency is characterized by pale green leaves as well as blossom and fruit rot.

Magnesium can be found in both dolomite and epsom salt. Dissolve 2 tablespoons of epsom salt in 1 gallon water water. Apply this mixture to your tomatoes, peppers and eggplants just as they start flowering for best results.


Calcium is an integral part of cell walls and root tips and is an often under discussed topic. Calcium deficiency shows up typically in younger tissues first, and include inward curling, pale young leaves, blossom end rot in tomato, and cavity spots in carrots.

Calcium be found in eggshellls and dolomitic lime. Eggshells can be crushed and applied directly onto the soil or into the compost. Follow the instructions on the package of your dolomitic lime when applying.


Sulphur is an important component of many enzymes used by plants in its growth and fruit production. Deficiency is most commonly seen in younger leaves.

Sulfur can be found in matchbooks (add them to your compost or underneath your transplants ) and epsom salt. Sulfur can be found at most garden centres as lime sulfur


Cover Image by Alex E. Proimos, used under its Creative Commons license.

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