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Tuesday, 28 June 2022
How do I know what fertilizer to use?

How do I know what fertilizer to use?

Surprisingly, lawn fertilizer isn’t popular amongst Canadian home gardeners. However, plants and grass that are given the right dose of fertilizer are healthier and more productive. The basics of how and why to apply fertilizer to your garden are covered in this article.

What are fertilizers?

Lawn fertilizers are a source of concentrated plant nutrition. The vast majority of fertilizers contain three main plant nutrients:

  • Nitrogen (N) which is required for the growth of green leafy plants.?
  • Phosphorus (P) which is necessary for the healthy growth of roots and shoots.?
  • Potassium (K) which is useful for flowering, fruiting, and overall hardiness.?

When purchasing fertilizer, it’s important to check the N:P:K ratio. A ratio of 20:20:20, for example, denotes a balanced fertilizer whereas a ratio of 10:12:24 denotes a high potassium fertilizer.

What types of fertilizer are available?

As a gardener, you may use a chemical lawn fertilizer to make plants or grass grow, or choose from a wide range of natural fertilizers, also known as organic fertilizers. Some of these come in liquid form, while others are granular fertilizers. 

Granular fertilizers have certain advantages since they last longer and are absorbed at the root level rather than through the leaves. On the other hand, liquid fertilizer can be sprayed directly onto the lawn surface and is ideal for use in regions where additional nutrients are required.

How do I know the nutrient ratio that’s right for my lawn?

Whether you’re using a natural or chemical fertilizer, you need to be aware of its nutrient ratio. A healthy lawn fertilizer, one with the right nutrient ratio, will promote a healthy lawn. 

Low nitrogen for new lawns

Phosphorus and potassium are key in a new lawn. Also, because the roots aren't ready to tolerate a lot of top growth yet, you need to go easy on the nitrogen. Make sure to choose a fertilizer with a low nitrogen content and a high potassium and phosphorus content. While normally costlier, it is necessary for fresh turf.

High nitrogen for healthy lawns

Choose fertilizers that are high in nitrogen but low in phosphorus and potassium for well-established healthy lawns. Healthy grass doesn't require a great deal of potassium or phosphorus.

More potassium for stressed lawns

If your grass is under stress, an increase in potassium can help alleviate the stress and make the grass stronger. Fertilizers that are high in nitrogen and potassium, but low in phosphorus, should be used.


Sustainable lawn maintenance tips that you should know


How do I find out about a lawn fertilizer’s nutrient ratio?

A fertilizer’s nutrient ratio is printed on the back of the package. The percentages of potassium, phosphate, and nitrogen are shown. For example, if the bag is labeled 30:10:20, it means that the fertilizer contains 30% nitrogen, 10% phosphate, and 20% potassium.

For most lawns, there is an ideal N:P:K ratio. Most lawns benefit from a 3:1:3 or 4:1:2 fertilizer ratio, but every lawn is different. Testing your soil is the best way to figure out exactly what your type of grass requires.

How does knowing the N:P:K ratio help me?

The numbers assigned to fertilizer nutrients, in the label mentioned on the package, represent their concentration. A fertilizer with an N:P:K ratio of 20:5:5, for example, contains four times more nitrogen than phosphorus and potassium. 

The concentration of all three nutrients in a 20:20:20 fertilizer is double that of a 10:10:10 fertilizer. The fertilizer numbers can be used to figure out how much fertilizer to apply to get 1 pound (453.5 g.) of the nutrient you want to add to the soil. If the fertilizer's numbers are 10:10:10, divide 100 by 10, and you'll find that you'll need 10 pounds of fertilizer to add one pound of nutrient to the soil. 

Similarly, If the fertilizer numbers are 20:20:20, divide 100 by 20 to find out how many pounds of fertilizer it will take to provide one pound of nutrient to the soil. The other values in a fertilizer containing only one macronutrient will be 0. If a fertilizer is 10:0:0, for example, it exclusively contains nitrogen.

Why is this important?

Now that you know what the numbers on the fertilizer package mean, you should understand why N:P:K is so important. To thrive, all plants require nitrogen, phosphorus, and potassium. A plant will die if it lacks one or more of these nutrients:

  • Nitrogen (N) is responsible for the majority of the plant's leaf growth.?
  • Phosphorus (P) is essential for root development as well as flower and fruit development.?
  • Potassium (K) is a nutrient that aids the plant's overall functioning.?

Knowing a fertilizer's N:P:K values helps you choose one that's right for the type of plants and grass that you're growing. If you're growing green veggies, for example, you might want to use a fertilizer with a higher nitrogen content to encourage leaf growth. If you're growing flowers, a fertilizer with a higher phosphorus content may be necessary to produce more blossoms.

How and when should I fertilize my lawn? 

You can fertilize your lawn manually or with a spreader. The former is tricky, because it's impossible to tell if you've applied enough fertilizer. A spreader, according to most lawn care professionals, can help you spread your fertilizer evenly across the surface and create better results.

To complete the task, you can use a number of spreaders. Shoulder or portable spreaders are perfect for non-rectangular gardens and are very easy to use. Spreaders with a mechanical push-along mechanism can also be used. Mechanical spreaders are better suited to large gardens that require large amounts of fertilizer. 

There are two types of mechanical spreaders: 
• Drop spreaders?
• Rotary spreaders. ?

Drop spreaders feature small holes on the underside, through which the feed drops onto the grass, whilst rotary spreaders include a spinning mechanism that sprays the fertilizer. Ideally, you should fertilize your lawn after it has been mowed. Similarly, you should avoid mowing it right after fertilization, as the fertilizer may not get properly absorbed.

How do I know if my soil is healthy?

To know if your soil is healthy, you should do a soil test. A soil test can help you assess the soil’s pH level and diagnose any nutrient deficiency. For example, most plants, flowers, grasses, and vegetables thrive in a slightly acidic soil. 

On the other hand, other plants such as azaleas, gardenias, and blueberries, require a higher level of acidity to thrive. A soil test can help you determine the acidity level and make the necessary adjustments. 

Soil samples can be taken at any time of year, but fall is the best time to do so. They are usually taken once a year or as needed. Many companies and gardening stores sell soil testing kits. In addition, lawn care companies can perform a soil test for you at a minimal cost.

When the soil is damp or has recently been fertilized, you should avoid having it tested. In order to test garden soil, you should use a small trowel to take thin slices of soil from several different locations (roughly a cup's worth each). 

Allow the slices to air dry at room temperature before storing them in a clean plastic container or Ziploc bag. The soil area should be labeled, as well as the date of the test. By testing your garden soil, you can take the guesswork out of fertilization.


How to improve your soil


Lawn maintenance services

EagleYard provides three lawn care packages to help your grass thrive. We apply lawn fertilizer, biostimulants, and calcium, as well as eliminate weeds and bug infestations. More importantly, this isn't a one-time fix. EagleYard offers service calls and routine check-ups if problems persist. If you are worried about your lawn and need assistance, feel free to get in touch with us.


Contact a garden expert now