Choosing the best lawn fertilizer can be a challenge because there are so many factors to consider, such as blends and NPK levels. In this guide, we’ll cover everything from reading NPK numbers to the best time to fertilize. Read on to discover how to improve the health and appearance of your grass.

Key Takeaways

  • Choosing the best lawn fertilizer for your grass depends on your soil and is different for every lawn.
  • NPK numbers indicate the percentage of essential nutrients in a fertilizer.
  • Soil tests are a great way to learn what your lawn needs to thrive.
  • Carefully follow fertilizer instructions to avoid harming your lawn.
  • The best times to fertilize your grass are late spring and early fall.
  • A 20-5-10 NPK ratio is good for spring fertilizing and a 25-5-5 quick-release low nitrogen fertilizer is great for late-fall.

How to Read Lawn Fertilizer Numbers

NPK numbers represent nitrogen (N), phosphorus (P), and potassium (K) ratios. Nitrogen, phosphorus, and potassium are major components of a healthy lawn. They each contribute to the growth and vitality of your grass differently.

Here’s an overview of the essential nutrients:

  • Nitrogen makes your lawn green and promotes growth.
  • Phosphorous stimulates the growth of strong roots and germination.
  • Potassium contributes to your grass’s disease resistance, hardiness, and drought resistance.
lawn food vs fertilizer
best lawn fertilizer

NPK numbers indicate the percentage of essential nutrients in the fertilizer. For instance, a fertilizer with an NPK number of 10-10-10 contains 10% nitrogen, 10% phosphorus, and 10% potassium. Each percentage is based on the weight of the fertilizer. If have a 50-pound bag of fertilizer and the NPK numbers are 10-10-10, you would multiply each percentage by 50 to determine how pounds of each essential nutrient there are in the bag.

Here’s an example:

10% (0.10) nitrogen x 50 lbs= 5 lbs of nitrogen
10% (0.10) phosphorus x 50 lbs = 5 lbs of phosphorus
10% (0.10) potassium x 50 lbs = 5 lbs of potassium

How to Find the Best Lawn Fertilizer

Every yard is unique, which means the type of fertilizer and how often you apply it varies from one yard to another. The soil in your yard may respond differently to a fertilizer your neighbour uses, even if you both have the same soil type.

Conducting a soil test is a great way to determine the best lawn fertilizer. Soil tests analyze essential elements, such as pH levels, potential diseases, and overall health. DIY soil test kits are an affordable and simple method to check if your soil lacks important nutrients.

what fertilizer to use in spring
Best Type of Fertilizers in Toronto

Best Type of Fertilizers in Toronto

Commonly recommended fertilizers for Toronto’s climate and soil include organic options. Organic fertilizers improve your lawn’s soil structure and nutrient content over time. ISR Gardening organic fertilizers are great for Toronto.

They’re free of chemicals and stimulate natural soil development. Slow-release fertilizers, which gradually release nutrients to plants, are also popular fertilizers for sustainable and efficient plant growth. To get the best fertilizer for your grass, you can consult local gardening experts such as ISR Gardening.

Comparing Different Fertilizers

Lawn Food vs. Fertilizer

Comparison PointsLawn FoodFertilizer
PurposeSpecifically designed for lawnsSuitable for all plant life
NutrientsBlend of nutrients with slow-releaseVarious nutrient ratios tailored to specific plant needs
CostTends to be more expensiveCost-effective
Application FrequencySeasonal applicationApplication varies based on lawn needs, can be more frequent
Environmental ImpactContains more natural and organic ingredientsCertain types of fertilizers contain synthetic chemicals

Lawn Starter Fertilizer vs. Regular Fertilizer

Comparison PointsLawn Starter FertilizerRegular Fertilizer
PurposeTurf establishment for newly seeded or sodded lawnsMaintain healthy grass throughout growing seasons
NutrientsHigher phosphorus content for root development and establishmentVarying ratios of nitrogen, phosphorus, and potassium
CostCan be costly depending on the size of the lawnCost-effective for ongoing lawn maintenance
Application FrequencyApplied during initial seeding or soddingApplied throughout the year, typically every 6-8 weeks
Environmental ImpactOverapplication can lead to phosphorus runoff and water pollutionOrganic and chemical variations available

Synthetic vs. Organic Fertilizer

Comparison PointsSynthetic FertilizerOrganic Fertilizer
PurposeIdeal for correcting nutrient deficiencies and rapid growthSustainable growth through slow-release nutrients
NutrientsHigh concentrations of nitrogen, phosphorus, and potassiumNatural nutrients from compost and manure
CostLower initial cost but requires more applicationsHigher initial cost but lasts longer
Application FrequencyApplied frequently during the growing seasonApplied less frequently throughout growing season
Environmental ImpactLeaching contaminates water sources, can cause nutrient runoff and algae bloomsMinimizes long-term pollution and environmental harm

How to Fertilize Your Lawn

Once you’ve identified the best fertilizer for your grass, all that’s left to do is start. Make sure you follow the instructions on the package carefully for proper application. After adding the the lawn food, remember to water your lawn to help the nutrients seep into the soil. Be careful not to use too much fertilizer, as it can damage your lawn.

Fertilizing Tips

  • If the forecast is calling for rain, hold off on using your fertilizer. Rain water provides hydration and essential nutrients that serve as a natural fertilizer.
  • Avoid fertilizing a wet lawn since the excess moisture can cause the fertilizer to wash away, leading to wastage and potential harm to the environment.
lawn starter fertilizer
Best Time to Fertilize Your Lawn

When Is the Best Time to Fertilize Your Lawn

The best time to fertilize your lawn is in the late spring and early fall. Fertilizing in the late spring helps promote healthy growth and prepares the lawn for the summer months. Fertilizing in the early fall helps strengthen the roots and prepares the lawn for the winter dormancy period.

The ideal choice for the best spring lawn fertilizer is a 20-5-10 NPK ratio. Newly planted lawns may need higher levels of phosphorus and potassium. Consider applying a slow-release nitrogen fertilizer in late May or early June, before the heat of summer, to help encourage regrowth.

A 25-5-5 ratio quick-release nitrogen fertilizer is the recommended choice for late-fall fertilization. For deeper root growth and a denser lawn, apply your fall fertilizer when the grass is no longer growing but is still green. If your lawn wasn’t as lush as desired in the previous season, consider using a 20-8-8 ratio for extra support.

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Next Steps to Find the Best Fertilizer

Finding the right lawn food for your grass can be a little overwhelming to start if you don’t have a green thumb yet. Fortinatelly ISR Gardening provides lawn fertilizer services in Toronto and the GTA. Contact our team to schedule the next best lawn fertilizer maintenance for your newly sodded grass.