How & When To Properly Apply Lawn Fertilizer [& Best Brands]

A lush, green lawn is every homeowner’s dream, but achieving it takes more than regular mowing and watering. To maintain your lawn’s health and appearance, you have to fertilize it regularly.

In this guide, we’ll show you everything you need to know about fertilizing your lawn, from choosing the right products to applying them at the best time for optimal results. So, let’s learn how to transform your lawn!

Why Lawn Fertilization Is Important

Grass, like any plant, relies on nutrients to grow. Your lawn’s soil naturally loses the essential elements that your grass relies on over time. Lawn fertilizers generally contain vital nutrients, such as nitrogen, phosphorus, and potassium, and can replenish the nutrients your lawn needs to grow dense and vibrant.

Phosphorus is excellent for strengthening the roots and supporting new grass development; potassium fortifies your lawn against environmental stressors; and nitrogen promotes rapid growth. Without them, it’s very likely for your lawn to become weaker and give room for weeds and pests to thrive.

However, there are other fertilizers that contain more components, such as micronutrients and herbicides, for specific use cases. We’ll look at some examples below.

Understanding Your Lawn’s Needs

Before fertilizing your lawn, you must assess your soil’s condition, understand your grass’s growth preferences, and see how you can best maintain its health and optimize growth.

Here’s what you should do:

1. Evaluate Your Lawn Type

Different grass types thrive in different climates and seasons, so knowing what’s growing underfoot is key.

• Cool-season grasses, such as fescue or Kentucky bluegrass, grow actively during the cooler months of spring and fall. They appreciate fertilizer when temperatures are mild.
• Warm-season grasses, such as Bermuda and zoysia, love the heat and grow most vigorously in late spring and summer; fertilize them then.

Beyond that, check which soil type you have.

• Sandy soil drains well and is easy to work with, but it struggles with nutrient and water retention.
• Clay soil retains moisture but is susceptible to compacting and hardening.
• Silty soil is also great at nutrient and water retention but can compact and may be prone to erosion.
• Loamy soil is ideal for most lawns as it combines the best characteristics of sand, clay, and silt.

2. Test Your Soil

A simple soil test should reveal its pH level, nutrient profile, and deficiencies you need to address. You can use soil testing kits to continuously monitor your lawn and to keep you in tune with its needs.

pH Level

Most grasses prefer a slightly acidic to neutral pH (6.0–7.0). If your soil is too acidic or alkaline, it’ll get in the way of nutrient absorption.

• You can raise the pH (make it less acidic) by adding lime (calcium carbonate) or dolomitic lime, which also provides magnesium.
• Similarly, you can lower the pH (make it less alkaline) by incorporating sulfur or aluminum sulfate. Compost can also help gradually lower pH over time.

The amount needed will depend on the current pH level and soil type, so be even in your fertilizer application and retest your soil after a few months.

Nutrient Deficiencies

Just like us, your grass needs a balanced diet of essential nutrients to thrive. When it’s deficient in some of them, it’ll show signs of stress, such as yellowing, stunted growth, or poor overall health.

Most fertilizers are NPK balanced, as nitrogen (N), phosphorus (P), and potassium (K) are the primary nutrients required for plant growth. Despite that, your lawn could show deficiency in:

• Iron (Fe): Essential for chlorophyll production, and its deficiency manifests as yellowing between the veins of young grass leaves.
• Magnesium (Mg): Crucial for photosynthesis. Without it, your grass will begin yellowing, starting from the older leaves.
• Calcium (Ca): Important for cell wall structure and stability. It’s responsible for ensuring that your grass’s stems aren’t weak and its growth isn’t distorted.
• Sulfur (S): Critical for protein synthesis. Its deficiency shows as uniform yellowing of the younger leaves.

Some fertilizers can address multiple deficiencies, whereas others target specific ones. Organic fertilizers, including compost, manure, and organic matter, deliver various nutrients over time while improving your soil’s structure and microbial activity.

3. Identify Lawn Problems

You might want to consider fertilizing your lawn if you notice that:

• It doesn’t grow evenly.
• It can’t maintain a deep green hue (or your grass’ healthy color).
• It doesn’t feel lush underfoot.
• It’s overrun by weeds or pests.

If you can address such issues early, you’ll prevent long-term damage and get back on track to having a lawn that turns heads.

How to Choose the Right Fertilizer

Based on the assessment of your lawn’s needs, the next step is to choose the right fertilizer to solve the problems plaguing it.

Here’s what you need to know:

Types of Fertilizers

Fertilizers come in many types and forms.

• Granular fertilizers come in pellet form and are great for beginners due to their slow-release formulas. Since they feed your lawn over time, it’s unlikely that you’ll accidentally over-fertilize it.
• Liquid fertilizers work faster. Mix them with water and apply them for a quick distribution of nutrients. However, they require regular application, preferably through irrigation systems.
• Foliar sprays are designed to be sprayed directly on the leaves of plants and are ideal for a quick correction of deficiencies, bypassing any soil-related issues.
• Organic fertilizers, such as compost, manure, and bone meal, are completely natural and improve soil health while feeding the grass.
• Synthetic fertilizers are precise and immediate in delivering results but require more care in application to avoid accidental overfeeding or nutrient runoff.

There are also micronutrient fertilizers that contain chelated forms of iron, zinc, manganese, and copper; complete fertilizers that provide a mix of primary, secondary, and micronutrients; and supplements that target specific micronutrient deficiencies, such as calcium and magnesium fertilizers.

If you’re eco-conscious, slow-release and organic fertilizers will be to your liking, as they minimize nutrient runoff and extend feeding times. Organic fertilizers also add nutrients while improving soil structure and microbial activity.

Key Nutrients

Fertilizer labels show the NPK ratio. Choose a fertilizer with the right nutrient balance to ensure that your soil is going to get exactly what it needs to thrive.

If your soil is deficient in micronutrients, opt for fertilizers that also include essential elements like iron, calcium, and magnesium. This will help replenish those elements and improve your soil’s health.

Seasonal Recommendations

Different seasons call for different fertilizer strategies.

Cool-Season Grasses

During winter, a balanced fertilizer can help wake up your lawn and encourage growth after winter dormancy. However, these grasses often go dormant in extreme heat, so a light application of nitrogen can help maintain health without overstimulating growth.

In the fall, a phosphorus-heavy formula will help prepare such grasses for winter and support root development for a strong return in spring.

Warm-Season Grasses

Warm-season grasses grow actively during hot seasons. Using a balanced fertilizer during spring will boost growth as temperatures rise, whereas a nitrogen-rich product will support vigorous growth during their peak season in summer.

They need less fertilizer during the fall, as they’ll go dormant in preparation for winter. During this season, applying a balanced formula suffices.

In short, avoid fertilizing during dormant periods, as it’s a waste of resources and can even harm your lawn. Try to sync your fertilization efforts with your lawn’s growth cycle.

How to Fertilize a Lawn

Here’s a step-by-step guide to fertilizing your lawn.

1. Prepare Your Lawn

Start by mowing your grass to an even height. Make sure you don’t scalp it too short—cutting a third of the grass blade’s length is enough. This is to allow the fertilizer to reach the soil more effectively.

Next, clear away debris like leaves, sticks, excessive clippings, and mulch that could block the fertilizer.

After, aerate your lawn (if you haven’t done so in a while), then lightly water it. Damp soil helps fertilizer granules break down and absorb better. You can skip this step if you’re using liquid lawn fertilizers or a foliar spray.

2. Choose and Prepare Your Fertilizer

Your fertilizer of choice will vary depending on your lawn’s needs, circumstances, and preferred method of application. Always read its label to understand how to apply it and what the ideal amount is.

A granular fertilizer can be loaded into a spreader for consistent coverage, whereas a liquid fertilizer should be mixed with water according to the instructions.

Note that overfertilization or patchy growth is a very common risk, especially with synthetic fertilizers or fertilizers that require precision.

3. Apply the Fertilizer

If you’re using granular fertilizer, load it into the spreader and walk your lawn in overlapping patterns to ensure full coverage. For small lawns, a drop spreader is precise; for larger areas, a broadcast spreader works best.

Foliar sprays should be sprayed directly onto the leaves. Liquid fertilizers are applied to the soil, either manually or through irrigation systems. Slow-release and organic fertilizers are also placed on the soil and left to decompose over time to release their nutrients.

Make sure you apply evenly to avoid streaking or missed patches and follow up with a light watering (in the case of non-liquid fertilizers) to help the fertilizer absorb into the soil. But be sure to avoid creating puddles.

4. Maintain a Schedule

Most fertilizers recommend reapplication every 6–8 weeks, but this varies based on your grass type and climate. Make sure you note your fertilization schedule to ensure your lawn consistently gets the nutrients it needs, and it’s as healthy as possible.

Fertilization Tips to Become a Pro

We’d like to share a few tips and faux-pas you must avoid before letting you jump into fertilizing your lawn.

• Never try to guess your lawn’s needs; you’ll just waste fertilizer and get inadequate results. Soil testing kits are inexpensive and will tell you exactly what your lawn needs to grow healthy, lush grass.
• One misconception homeowners have is that applying more fertilizer equates to better results. More isn’t better—it’s harmful. Stick to recommended application rates.
• Never ignore seasonal timing. Fertilizing during dormancy wastes money and resources, so make sure to learn your grass’s growth cycle.
• Patchy lawns are often the result of careless spreading. Take your time with the application, or use a spreader to ensure even coverage.
• It’s much harder to deal with weed growth and pests. So, maintaining your lawn’s health through proper habits and frequent fertilizing will save you money and frustration in the long term.
• Avoid applying fertilizer—especially synthetic ones—before heavy rain to prevent runoff into storm drains.
• Remember that fertilizing isn’t a one-size-fits-all solution to your lawn’s problems. Combine it with healthy lawn care habits, such as aerating, overseeding, deep watering, and mowing, to get the garden of your dreams.

Grow Green with SunCo Lawns!

Fertilizing your lawn may seem daunting, but with the right tools, knowledge, and timing, it becomes a straightforward and rewarding task.

If you’d rather leave the hard work to the experts, SunCo Lawns is here to help. From custom fertilization plans to year-round lawn care, our team ensures your lawn stays healthy and stress-free. Contact us today if you’re ready to transform it into a paradise!