Does your lawn look a little…meh? You water it, you mow it, but that deep, vibrant green just isn’t showing up. You’ve probably heard that nitrogen is the secret ingredient for a lush carpet of grass. It’s true! Nitrogen fuels the green growth we all crave for our yards.
But here’s the tricky part: walking down the fertilizer aisle can feel like a maze. Slow-release versus quick-release? Ammonium sulfate or urea? Choosing the wrong nitrogen fertilizer can lead to burnt grass, wasted money, or a lawn that looks great for two weeks and then fades. You want consistent results without the guesswork.
This guide cuts through the confusion. We will break down exactly what nitrogen does for your grass and show you how to pick the perfect type for your soil and your goals. By the end, you will feel confident knowing you are feeding your lawn exactly what it needs to thrive all season long.
Let’s dive into the essential details of lawn nitrogen fertilizer so you can finally achieve that envy-inducing green.
Top Lawn Nitrogen Fertilizer Recommendations
- Scotts Turf Builder Lawn Food feeds and strengthens grass to help protect against future problems
- Fertilizer builds strong, deep roots and improves the lawn's ability to absorb water and nutrients (vs. unfed lawn)
- Apply lawn care product to a wet or dry lawn
- Grass fertilizer works on any grass type
- One 12.5 lb. bag of Scotts Turf Builder Lawn Food covers 5,000 sq. ft.
- Bonus brochure includes seasonal application timing, spreader settings, and tips for lawns, gardens, and trees.
- You don’t have to worry about streaks, stripes, or accidentally burning your lawn when you use Milorganite fertilizer!
- Milorganite contains virtually no salts, so it won’t burn your lawn, trees, shrubs, or plants, even in the hottest temperatures or driest conditions.
- Milorganite's iron greens without staining. Grass needs iron for the long-lasting, deep, vibrant green lawn you want. Milorganite delivers organically complex iron throughout the feeding period and won’t stain concrete, unlike iron salts in some synthetic fertilizers.
- Milorganite’s slow-release plant food formula provides nitrogen and other nutrients for up to 8-10 weeks after application and does not need to be watered in. Covers 2,500 Sq. Ft.
- Easy to Use: Our 28-0-0 Lawn Fertilizer Food comes with an attached sprayer that applies the perfect ratio of product for lawn applications. Covers up to 3,200 square feet, when using the attached sprayer
- Liquid Fertilizer 28-0-0 contains 28% Nitrogen. Nitrogen is a major component of chlorophyll where lawns get their green coloring. Nitrogen encourages growth for a dense attractive lawn
- The Power of Quick Release and Slow Release Nitrogen Fertilizer: 70% quick-release nitrogen to provide quick nutrient absorption 30% slow-release nitrogen keeps your lawn fed in between applications
- Can Be Used on All Grass types: Including Bermuda, St. Augustine, Zoysia, Buffalo, Centipede, Florida Palmetto, Bahia, Fescue, Ryegrass & Kentucky Bluegrass.
- High Nitrogen Formula: This High Nitrogen fertilizer was developed to perk up the lawn, by quickly correcting a Nitrogen deficiency. Nitrogen Encourages Greening & Growth if a nutrient deficiency is present
- Scotts Green Max Lawn Food is a dual-action fertilizer and iron formula that feeds your lawn and provides deep greening in just 3 days
- This lawn care product contains 5% iron, a micronutrient that enhances the greening process for fast results
- Apply this fertilizer plus iron supplement to any grass type in the spring, summer, or fall
- Guaranteed not to stain concrete, driveways, or other surfaces surrounding your lawn (when used as directed)
- One 16.67 lb. bag of Scotts Green Max Lawn Food covers 5,000 sq. ft.
- 28-0-0 Liquid Lawn Food Nutritional Supplement: High Nitrogen Formula. Nitrogen aids in the formation of chlorophyll where plants get their green coloring. The addition of Nitrogen encourages vigorous growth for the development of a dense attractive lawn.
- The Power of Quick Release and Slow Release Nitrogen Fertilizer: 70% quick-release nitrogen to provide quick nutrient absorption 30% slow-release nitrogen keeps your lawn feed in-between applications.
- 28-0-0 contains 28% Nitrogen. Nitrogen is a major component of chlorophyll where plants get their green coloring. Nitrogen encourages vigorous growth for the development of a dense attractive lawn.
- Can Be Used on All Grass types: Including Bermuda, St. Augustine, Zoysia, Buffalo, Centipede, Florida Palmetto, Bahia, Fescue, Ryegrass & Kentucky Bluegrass.
- Application Rates for Lawn, Garden and Indoor Plants: Versatile Formula can be used on turf grass, ornamentals, young plants, flower beds, potting soil, young trees, garden and hardy plants.
- Liquid Lawn Fertilizer Booster: Iron and Nitrogen Blend. Lawn Energizer booster provides essential nutrients needed to darken the green of your lawn
- Fertilizer with Attached Sprayer: liquid lawn booster treatment in a ready-to-use hose end sprayer covers 3,200 square feet
- Lawn Energizer 6-0-0 Contains 6% Nitrogen: Nitrogen encourages growth for the development of a dense attractive lawn
- Blended with 5% Iron: This concentrated solution is great for enhancing and deepening the green of your lawn
- Use Alongside Fertilizer Program. Lawn Energizer Liquid Fertilizer can be used with your current fertilizer program. Great as a supplement to granular fertilizer programs for a quick plant uptake
- You don’t have to worry about streaks, stripes, or accidentally burning your lawn when you use Milorganite fertilizer!
- Milorganite contains virtually no salts, so it won’t burn your lawn, trees, shrubs, or plants, even in the hottest temperatures or driest conditions.
- Milorganite's iron greens without staining. Grass needs iron for the long-lasting, deep, vibrant green lawn you want. Milorganite delivers organically complex iron throughout the feeding period and won’t stain concrete, unlike iron salts in some synthetic fertilizers.
- Milorganite’s slow-release plant food formula provides nitrogen and other nutrients for up to 8-10 weeks after application and does not need to be watered in. Covers 2,500 Sq. Ft.
- Milorganite can be safely used in lawns, flowers, shrubs, trees, and fruit and vegetable gardens, promoting strong roots and sturdier stems. It provides the nutrients every garden needs to grow the biggest and greatest abundance.
- Ideal for lawns with nitrogen deficiencies
- Contains both quick- and slow-release nitrogen
- Can be used any time during the growing season
- Small particle size for complete and uniform coverage
- Safe for all turf types
The Green Thumb’s Guide to Lawn Nitrogen Fertilizer
Getting a lush, green lawn takes more than just regular mowing. Nitrogen fertilizer is the secret ingredient that fuels vibrant growth. This guide helps you pick the best product for your yard.
Key Features to Look For
When shopping for nitrogen fertilizer, several features make a big difference in how well it works and how long the results last.
1. Nitrogen Release Rate
- Quick-Release (Fast-Acting): These feed your lawn right away. They give you a fast green-up, usually within days. However, the effect fades quickly.
- Slow-Release (Controlled-Release): These bags contain coatings or special compounds that break down slowly over weeks or months. They provide steady feeding and reduce the risk of burning your grass. This is often the better choice for long-term health.
2. N-P-K Ratio
You will always see three numbers on the bag, like 20-5-10. This is the N-P-K ratio:
- N (Nitrogen): This is the most important number for green growth. Higher is usually better for color.
- P (Phosphate): Helps with root development. Lawns usually need less of this, especially established ones.
- K (Potash): Supports overall plant health, disease resistance, and stress tolerance.
For general feeding, look for a product with a high first number (Nitrogen).
3. Granule Size and Coating
Smaller, uniform granules spread more evenly. If you buy a slow-release product, check what kind of coating it uses. Polymer-coated granules usually offer the most predictable feeding schedule.
Important Materials in Your Fertilizer
The source of nitrogen matters. Different materials feed your lawn at different speeds.
Synthetic Sources (Fast Growth)
- Urea: A common, fast-releasing source. It works quickly but must be watered in well to avoid burning the grass blades.
Organic Sources (Slow and Steady)
- Milorganite or Feather Meal: These break down naturally with the help of soil microbes. They feed slowly and improve soil structure over time.
Factors That Improve or Reduce Quality
The quality of your fertilizer directly affects your lawn’s health.
What Improves Quality?
- High Water Solubility: For fast-release types, high solubility means the nutrients dissolve quickly so the roots can absorb them fast.
- Inclusion of Micronutrients: Some premium fertilizers include small amounts of iron (for deep color) or sulfur.
What Reduces Quality (and Causes Problems)?
- Poor Coating Consistency: If slow-release granules have inconsistent coatings, some release too fast, and others release too slow.
- Excessive Salts: Fertilizers high in soluble salts can pull water out of the grass roots, causing “fertilizer burn.” Always follow the application rate strictly.
User Experience and Use Cases
How you use the fertilizer depends on your lawn’s needs and your schedule.
For Quick Fixes (Spring Green-Up):
Use a high-nitrogen, fast-release product early in the season. This gives your dormant grass the sudden boost it needs to recover from winter.
For Season-Long Health:
Choose a slow-release formula for your main applications during the growing season. This prevents those sudden growth spurts followed by yellowing.
For New Lawns:
Look for a “starter fertilizer” that has a higher middle number (Phosphorus) to encourage strong root establishment.
10 Frequently Asked Questions (FAQ) About Lawn Nitrogen Fertilizer
Q: How often should I apply nitrogen fertilizer?
A: Most lawns benefit from three to four applications per year, spaced about 6 to 8 weeks apart during the growing season. Always check the bag for specific timing.
Q: Can I put down too much nitrogen?
A: Yes, absolutely. Too much nitrogen causes rapid, weak growth and significantly increases the chance of burning your lawn, turning it yellow or brown.
Q: What is the ideal time of year to apply the first fertilizer?
A: Apply the first feeding when the grass starts actively growing after dormancy, usually when daytime temperatures consistently reach 55–65°F.
Q: Does fertilizer need to be watered in?
A: Yes, always water lightly after applying granular fertilizer. This moves the nutrients off the blades and into the soil where the roots can reach them, preventing burns.
Q: Will organic fertilizer work as fast as synthetic?
A: No. Organic fertilizers rely on soil microbes to break them down, so they work much slower than synthetic options.
Q: What do the numbers on the bag (like 25-0-5) mean?
A: They show the percentage by weight of Nitrogen (N), Phosphate (P), and Potash (K) in the bag, in that order.
Q: Is it better to use a liquid or granular fertilizer?
A: Granular is easier for beginners and provides longer-lasting feeding. Liquid offers very fast results but requires more frequent application.
Q: Can I use a fertilizer with a high Phosphorus (P) number?
A: In many areas, using high-P fertilizers on established lawns is restricted by law because excess phosphorus runs off into waterways and causes pollution.
Q: What is “weed and feed” fertilizer?
A: This product combines nitrogen fertilizer with a weed killer (herbicide). You apply it when weeds are actively growing.
Q: Does rain wash away nitrogen fertilizer?
A: Heavy rain shortly after application can wash away fast-release nitrogen before the grass absorbs it, leading to runoff and wasted product.