Understanding Fertilizers

Want to know what the three numbers on the bag means? How much you should use? What type is best? Read on below to learn more about fertilizers.(This page will be updated with new information shortly!)

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NPK (the three numbers on the bag), what do they mean? And why does it matter?

NPK is simple the naming convention for three most important nutrients for your lawn, Nitrogen, Phosphorus and Potassium (the letters are based on the molecular structure!). Every common fertilizer has a mixture of these three nutrients, but now lets learn more about them.

Nitrogen (N)

Nitrogen is the most important nutrient for your lawn, and is usually what fertilizing programs are based around. Nitrogen affects both shoot and root growth, and can stimulate improved colour, stress relief and pest control. Nitrogen also moves more freely through the soil versus other nutrients and because of this more applications are required in general. If you want more growth in your lawn this year, Nitrogen is a key component to that.

Phosphorus (P)

While phosphorus has several important jobs in your lawn the main aspect that is considered is improved root growth. This is why when looking at "starter" fertilizers for new seed growth you will see a larger P number in the NPK rating. Phosphorus does not move as readily through most soils and therefore does not usually need to be applied as often as Nitrogen or Potassium.

Potassium (K)

Think of Potassium as a vitamin for your lawn, helping it to build over health and strength, improve photosynthesis, and overall become more vigourous. It helps to improve winter hardiness and wear tolerance as well. Like Nitrogen it does move through the soil more readily meaning more applications may be required, but not to the level of Nitrogen. Potassium is another important nutrient for your lawn.

But how much do I need?

The simple answer is to follow the rates listed on the bag, but there is a little more to it. Nitrogen is the nutrient used to base most fertilization calculations. Most turf types need between 2-4lbs of Nitrogen per 1000sqft per year. If the bag says 25-0-0 that means it is 25% Nitrogen. This means you would need 16lbs of the fertilizer to get 4lbs of Nitrogen.16lbs * .25 = 4.If you have a 2000sqft lawn you would double it, a 500sqft lawn, halve it. One of the most common ratios for NPK nutrients is 4-1-2 meaning you would use 25% as much Phosphorus and 50% as much Potassium when compared to Nitrogen.

This is just a basic understanding of calculating fertilizer amounts. The Lawn Medic is here to help with any questions you have. Want to make things easy? Try our fully planned programs!

The importance of Biostimulants

When digging deeper into lawn fertilization you will often find mention of Humic and Fulvic acids, as well as things like Kelp and seaweed. While these may not sound like things needed for your lawn, they are proven to help. Humic and Fulvic acids help your lawn absorb more nutrients from other fertilizers, fight stress, promote growth through stimulating plant hormones. Sea based stimulants like kelp are all natural and provide important minerals, amino acids and vitamins that help your lawn grow stronger both and below the soil. At The Lawn Medic we have all of these products available individually and in our plans and packs. Take a look or reach out to use to discuss how adding these biostimulants can help your lawn this year.

Secondary Nutrients, important but usually already there.

Secondary nutrients are important for your lawn, however they are usually found in sufficient quantities your soil already meaning fertilization with them are not as important. However if they are found to be lacking through a soil test it is important to rectify the deficiency. A lot of fertilizers include some small amount of these nutrients in order to make sure your lawn has what it needs to thrive. The Lawn Medic carries fertilizers with these included, and on their own allowing for exact treatments to be done when required.

Sulfur (S)

Sulfur is important in the production of proteins in plants, the metabolic function of your lawn, as well as in increased root growth. A lack of Sulfur can lead to chlorosis or yellowing of your lawn. Sulfur can also be used to lower the pH level of your soil if required.

Magensium (Mg)

Magnesium is a key nutrient in helping with the photosynthesis of your lawn, turning chlorophyll into energy which helps maintain a dark green colour in your lawn. Magnesium also helps transport carbohydrates to other parts of the plant. Purpling of your lawn ca be a sign of a deficiency.

Calcium (Ca)

Calcium is an important nutrient for the strength of the grass and roots. It is usually quite abundant in soils, but is not very mobile and therefore can be lacking in newer plants. Calcium can also be used to adjust pH levels in soil if needed.

Micronutrients

The micronutrients needed for your lawn are Iron (Fe), Copper (Cu), Manganese (Mn), Zinc (Z), Boron (B),Molybdenum (Mb) and Chlorine (Cl). In most situations micronutrient adjustment is not required as lawns with issues usually need adjust of macro (NPK) and secondary nutrients first. But using a soil test can reveal micronutrient deficiencies which can be tackled through speciality fertilizers in most cases. Iron is one micronutrient that you will see in more fertilizers because it helps to create a deeper green colour in your lawn, but if used too much it can also cause damage. Some studies also report that it can be beneficial in fighting fungus and pests as well.

Our Plans

We have developed our plans to take all of this information and put it into easy to packages. No guess work on how much of what nutrient to use, everything is pre-measured and ready to go. Ready to learn more?

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