Achieving Dark Green Grass: Fertilizer Solutions

By: Ken Wilson

Dark green grass is the number one way to give your neighbors lawn envy! So, what fertilizer should you use, and what’s the secret to making your grass the most lustrous on the block? Besides grass type and proper watering, you’ll need specific macro and micronutrients to achieve your greenish goals.

The secret to dark green grass is using a high-nitrogen, low-phosphorus fertilizer combined with an iron supplement. Iron is the main component that turns your grass darker. Nitrogen and iron increase chlorophyll formation, which gives your grass color.

Choosing the correct fertilizer for your lawn to make it greener is only part of the process. To get your desired color, you must understand what macronutrients contribute to chlorophyll production and how much it should be used. We’ll also cover a few tips to guarantee that you get the best results!

What Fertilizer Makes Grass Dark Green?

You’d quickly think that a general fertilizer will give you the radiant hue you seek, but that is only part of the equation. Fertilizer with high nitrogen levels and lower phosphorus is the first step in the recipe. However, liquid or granular iron is the main element to getting your lawn dark green.

How Nitrogen and Iron Contribute to Lawn Color

Understanding how these critical nutrients work will give you a better understanding of how to reach your turf goals.


The more chlorophyll a plant has, the greener it becomes because of photosynthesis. Nitrogen plays a vital role in chlorophyll production. This macronutrient also helps your grass grow denser and lusher, which promotes a greener appearance. The fuller the grass is, the darker it is.

However, it is vital to note that too much nitrogen can lead to quick yet weak growth and an increased susceptibility to diseases. Luckily, we’ll cover how much to add to your fertilizing process. You can add a plant growth regulator (PGR) to ensure no harm is done.


Iron is essential to dark green grass because it gives a bluish tinge. This micronutrient also contributes to the synthesis of chlorophyll. With sufficient iron levels, grass produces an abundance of chlorophyll, which develops a rich, dark color.

Iron helps grass resist environmental stresses like diseases and pests, which promotes health. Healthy grass equals a greener lawn. Iron primes your grass to absorb and use macronutrients efficiently. This is especially helpful for greenness when paired with nitrogen.

If your main reason you desire for dark green grass is chlorosis (a lack of chlorophyll that causes grass to turn yellow or pale green), iron is your answer!

While iron is fundamental for greenness, not all lawns need additional supplementation. Your soil may already have sufficient iron levels, but you can conduct a soil test to determine deficiency. Although this micronutrient is fantastic, too much iron can cause your grass to turn blue or black.

A Recipe for a Dark Green Lawn

Now that you know the key macro and micronutrients, this recipe guideline will give you a solid idea of how to fertilize your lawn for quick results!

Method # 1:

You’ll need:

  • 1 gallon of boiling water per square foot
  • 0.2 lbs of 46% nitrogen fertilizer per square foot
  • 1.5 oz of iron per square foot (or as per product recommendation)
  • (Optional) 5 ml of Plant Growth Regulator per 1000 sq. ft.
  • A liquid sprayer

You should use hot water for this¬†recipe; otherwise, your nitrogen, iron, and PGR won’t dissolve properly. Note that iron will stain your concrete orange and is nearly impossible to remove. Be extra cautious when you spray the solution and ensure that the fertilizer you use is suitable for foliar application.

This liquid method gives you the fastest results, as soon as 24 hours, but lasts only about three weeks.


  • Add the nitrogen, iron, and PGR one by one into the hot water, but mix thoroughly each time before you add the next ingredient.
  • Filter out the sediment.
  • Pour the strained liquid into your sprayer.
  • Apply evenly onto your lawn.

Method 2:

You’ll need:

  • 1 lb of nitrogen fertilizer per 1000 sqft (You can calculate the weight from the Nitrogen-Phosphorus-Potassium ratio found on your fertilizer)
  • Granular fertilizer spreader
  • Liquid iron (apply as per product recommendation)
  • Liquid sprayer

This method takes about a week to see results as granular nitrogen takes longer to settle into your lawn. Still, the results are longer lasting as granular fertilizers are slow-release, which maintains nutrient production for longer.

If you’re happy to wait for your grass to turn emerald, you can replace the liquid iron with a granular one for a prolonged effect.


  • Apply your granular fertilizer carefully and evenly using your spreader.
  • Mix your liquid iron with hot water per the product instructions and pour it into your sprayer.
  • Spray your lawn with the iron solution.
  • Water the grass.

Choosing the Right Fertilizer Products

These 8 best fertilizer products will help you achieve the most gorgeous dark green grass. It’s always best to follow the directions on the product. These options can either be used for or instead of methods #1 and #2.

1. Scotts Turf Builder Lawn Food: Buy the liquid version if you want to use it in method #1. You can use 3 lbs. per 1,000 sq. ft. in method #2.

2. Scotts Green Max Fertilizer Granules: This fertilizer doesn’t require an additional iron supplement, and you can use it independently instead of methods #1 and #2.

3. Flagship Professional Fertilizer (24% Nitrogen): Use it for method #2, which requires 4 lbs. per 1000 sq. ft.

4. Milogranite All-Purpose Fertilizer: A slow-release, high-nitrogen fertilizer that can be used for method #2.

5. Ironite Mineral Supplement: This is a less harsh mineral supplement you can use along with other fertilizers instead of the liquid iron in both methods.

6. Pendleton Turf Supply All Purpose Liquid Iron Fertilizer: The directions recommend using 3 oz per 1000 sqft. You can use this product for methods #1 and #2.

7. Simple Lawn Solutions Liquid Iron Fertilizer: You’ll need 10 oz per 1000 sqft. Mix with water as indicated by the product instructions. You can use this liquid option with method #2.

8. Earth Science Fast-Acting Iron: This is a natural granular option that you can use in method #2 instead of liquid iron. The results will show up slowly but last longer.

Final Thoughts

Are you ready for the grass to be greener on your side? Using a nitrogen and iron combination, you’ll have an emerald turf for all to marvel at. Both methods mentioned work wonders, but a few products can be used instead – as they merge nitrogen and iron without needing to do it yourself.

About the author 

Ken Wilson

Long time career in the home services industry from remodeling to patio construction. Currently residing to in SWFL and active contributor to multiple home & garden publications.