High-Nitrogen Fertilizer for Plants | Guide for Proper Use

If you have a large amount of leafy green vegetables such as spinach or Brussels sprouts, you will likely require a significant amount of high-nitrogen fertilizer to ensure successful growth of the plants.

If you want a healthy, lush lawn, nitrogen is key. That said, high-nitrogen fertilizer is not for every plant, and many plants might not need it all. 

What is high-nitrogen fertilizer? High-nitrogen fertilizer is any fertilizer with more nitrogen content than phosphorus and potassium. You can check the NPK label on the package. The first digit refers to the amount of nitrogen in the fertilizer. This type of fertilizer is more suitable for lawns and leafy greens.

When would you need high-nitrogen fertilizer, and how would you know that your plants have nitrogen deficiency? Read more to find the answers to all of these questions and more.

High-Nitrogen Fertilizer

The bag of fertilizer you buy usually will have a set of 3 digits separated by dashes.

This is called the NPK number (nitrogen, phosphorus, and potassium respectively), and it can be 10-10-10, 6-6-6, or something similar for balanced fertilizers.

A high-nitrogen fertilizer will have a label such as 12-3-3, which means that it has 12 percent nitrogen but only 3 percent phosphorus and 3 percent potassium. 

What Is High-Nitrogen Fertilizer Good For?

Your lawn will benefit from a high-nitrogen fertilizer applied several times throughout the growing season.

High-nitrogen fertilizer is also good for leafy vegetables since it promotes lush green leaves and speeds up the growth of these leaves and stems.

Nitrogen in the soil often triggers a growth spurt in many plants and allows the plant to have dense foliage.

When To Use High-Nitrogen Fertilizer

You should definitely use high-nitrogen fertilizer when your plants show symptoms of nitrogen deficiency.

Lawns and leafy greens in particular benefit from lots of nitrogen. Other plants need a lot of nitrogen in the soil, so you would feed them with this type of fertilizer.

Fertilizer Nutrients

Fertilizers have two types of nutrients. The main macronutrients are nitrogen, phosphorus, and potassium. These are the basic nutrients that most plants need in varying amounts.

The other types of nutrients are micronutrients, which include iron, boron, calcium, and magnesium among others. Many plants only need these nutrients in trace amounts, and some don’t need them at all.

Nitrogen Deficiency Symptoms

You will know when your plants have a nitrogen deficiency. The first sign is stunted growth. The plants might stop growing altogether due to the absence of nitrogen in the soil.

Also, the leaves will turn yellow. New leaves will often be smaller than the average leaves of the plant. The stalks become soft and bend under the weight of the leaves and flowers.

If the plant doesn’t get nitrogen soon, it becomes prone to diseases and might die.

What Is the Fastest Way To Add Nitrogen to Soil?

The fastest way to add nitrogen to the soil is to apply a fast-release nitrogen-high fertilizer.

Usually, the nitrogen becomes available for the plant immediately once it dissolves in water. 

What Happens When You Add Too Much Nitrogen to Soil?

Too much nitrogen in the soil can stress out the plants with fast growth spurts. Some plants will become leggy as they absorb too much nitrogen.

For flowering plants and fruits, the harvest will suffer as the plants grow more leaves and stems than flowers.

What Is Considered High-Nitrogen Fertilizer?

High-nitrogen fertilizer is a fertilizer that contains high amounts of nitrogen and little or zero amounts of phosphorus and potassium.

Any fertilizer with over 20 units of nitrogen per weight is considered high-nitrogen.

However, if the fertilizer contains 20 units of the other two macronutrients as well, then it’s considered a balanced fertilizer, though it still contains high amounts of nitrogen. 

Highest Nitrogen Fertilizer

Both urea and ammonium sulfate are considered high-nitrogen fertilizers. Urea in particular has the label 46-0-0, which is pure nitrogen. Ammonium sulfate is also just nitrogen with the label 21-0-0.

These fertilizers release their nitrogen quickly in the soil, making it accessible to the roots of the plants once the soil is wet.

A woman wearing gloves adding granular fertilizer to bare soil before planting.

High-Nitrogen Fertilizer for Lawns

Grass often needs a lot of nitrogen to stay lush green. The following two fertilizers are specifically developed for lawns.

Since turf grass doesn’t flower, then it has no need for phosphorus. As long as you feed the grass high-nitrogen fertilizer, you’ll have a green lawn.

Pennington UltraGreen 30-0-4 Lawn Fertilizer

With more nitrogen than potassium and zero phosphorus, this fertilizer feeds the grass and keeps it lush and green.

It is suitable for all types of turf grass and is easy to apply. It also improves the lawn’s tolerance for extreme heat and extreme cold.

Pennington UltraGreen Lawn Fertilizer, 14 LBS, Covers 5000 Sq Ft

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Urea Fertilizer 46-0-0

If you’re looking for the highest and fastest nitrogen fertilizer, you can’t go wrong with this one. Just follow the instructions on the package.

It contains high levels of nitrogen and can be used with lawns, gardens, and even organic farming.

Urea Fertilizer 46-0-0 | Plant Food for Indoor/Outdoor Flowers & Organic Gardens

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Slow-Release High-Nitrogen Fertilizer

Slow-release high-nitrogen fertilizer keeps feeding the grass for weeks after each application.

This type of fertilizer protects the plants against fertilizer burn as well as the stress that comes from growth spurts after each application.

Greenway Nitroform 39-0-0

This fertilizer only provides nitrogen as it contains zero phosphorus and potassium. It releases the nitrogen into the soil slowly so it wouldn’t stress out the grass and keep it growing at a normal pace.

This fertilizer has three types of nitrogen: urea nitrogen at 3 percent, water-soluble nitrogen at 7.5 percent, and insoluble nitrogen at 28.5 percent.

Nitroform 39-0-0 Slow Release Nitrogen Fertilizer, 5lbs

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High-Nitrogen Fertilizer for Vegetables

Unlike grass, vegetables still need the other two macronutrients even if in smaller amounts than nitrogen. So if you’re looking for a high-nitrogen fertilizer for vegetables, this one will do the job:

Fitleaf Plant Energy Boost 20-5-10

For leafy green veggies, Fitleaf promotes the healthy growth of the leaves without stressing the plant out. It comes in the form of granules but is easy to dissolve in water and apply.

The fertilizer contains adequate amounts of phosphorus and potassium to feed the vegetables in addition to the high content of nitrogen.

Fitleaf Plant Energy Boost 20-5-10 (3.53 oz)

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Natural Nitrogen Fertilizer

You don’t have to buy high-nitrogen fertilizer every time your leafy veggies need a nutritious boost. Some of the natural materials that you usually throw in the trash are surprisingly rich in nitrogen.

Here’s a list of some of the natural nitrogen fertilizers you can use in the garden.

  • Coffee Grounds: Not only are recycled coffee grounds rich in carbon and nitrogen, but they also improve the acidity of the soil.
  • Eggshells: Wash eggshells, and crush them before mixing them into the soil. They provide slow-release nitrogen and calcium and reduce the acidity of soil.
  • Grass Clippings: Instead of throwing away grass clippings, make tea from them, and feed the plants with the nitrogen-high solution.
  • Blood Meal: You can buy blood meal for your nitrogen-hungry plants as it’s one of the richest naturally nitrogen-high fertilizers. 
  • Composted Manure: Composted manure contains higher levels of nitrogen than aged manure. Additionally, that nitrogen is readily available for the plants once mixed into the soil.

What Natural Fertilizer Has the Most Nitrogen?

If you’re looking for a natural fertilizer with high levels of nitrogen, then blood meal should be your first choice.

With over 13 percent nitrogen, plants will benefit from the quickly released nitrogen. You will see the result in just a matter of days.

Homemade Nitrogen Fertilizer for Plants

One of the easiest homemade nitrogen fertilizer recipes is grass clippings tea. The next time you mow your lawn, don’t throw away the grass clippings.

As long as they’re free from chemicals and have not been sprayed with pesticides, you can make a good fertilizer by boiling them in water. Here’s how.

  1. Wash a 5-bucket gallon with water.
  2. Fill one-third of the bucket with grass clippings.
  3. Add rainwater to fill the rest of the bucket.
  4. Cover the bucket, and let it sit in a dry place for two weeks. Stir it every few days.
  5. After two weeks, strain the grass clippings, and keep the tea.
  6. When applying it to plants, add one part of grass tea to 5 parts of water.

Final Thoughts

Leafy green veggies and lawn grass are some of the plants that relish high-nitrogen fertilizer.

Favor slow-release nitrogen fertilizers over the ones that release the nitrogen too fast to avoid stressing out the plants with sudden growth spurts.