How to Add Nitrogen to Soil


When I learned that the soil in my garden is somewhat nitrogen, deficient, I decided to learn how to add nitrogen to soil. Fortunately there are lots of ways to add nitrogen to the lawn and garden.

Here are six easy ways to add nitrogen to soil:

  1. All-purpose organic plant fertilizer with a high nitrogen content (NPK)
  2. Lawn organic fertilizer with a high nitrogen content (NPK)
  3. Certain manures (poultry manure, bat guano, worm castings)
  4. Plant-based products (seaweed, corn gluten meal, fruit vinegar)
  5. Fish & Animal by-products (fish emulsion, feather meal, blood meal)
  6. Homemade compost enriched with coffee grounds and yard clippings

Read on to learn how to add each type of nitrogen-rich plant food and choose the best way to start adding nitrogen to your soil.

How to Add Nitrogen to Soil - Wheelbarrow, Rake, and Garden Soil

Specific Ways to Add Nitrogen to Soil

It seems as if nitrogen deficiency is the most common nutrient deficiency in residential gardens. There are lots of ways to fix nitrogen deficiency in soil. You can make high nitrogen fertilizer with a generic organic product or buy specialized nitrogen-rich fertilizer.

NOTE: Before you start to add nitrogen to soil, make sure your soil actually needs it! To know if your soil needs nitrogen or not, get a soil test done. Call your local State Extension office or use a soil collection kit which can be sent away for laboratory testing.

1. All-Purpose Organic Plant Fertilizer With a High Nitrogen Content (NPK)

High-quality all-purpose organic fertilizer blends are a versatile way to increase the amount of nitrogen available to your lawn and garden plants. All-purpose fertilizer comes in several formats, including granular bits, water-soluble powder, and packaged liquid. The percentage of total nitrogen is listed as the first number (N) in the NPK ratio for each fertilizer.

Here are some great high-nitrogen organic plant food options:

Espoma Plant-Tone Organic Fertilizer (5-3-3)

Espoma Plant-Tone Organic Fertilizer (5-3-3) is one of the most popular all-purpose organic fertilizer blends. Espoma Plant-Tone has a guaranteed minimum amount of 5% total nitrogen. This well-balanced fertilizer is very versatile and can be used on all flowers, vegetables, trees, and shrubs.

Plant-Tone is derived from Feather Meal, Poultry Manure, Bone Meal, Alfalfa Meal, Greensand, Humates, and Potash. Plant-Tone also contains beneficial bacteria (Bio-Tone Microbes).

Established trees and shrubs can be fertilized with Espoma Plant-Tone in the spring. It’s quite easy to apply – simply sprinkle onto the soil under the plant and then water the area. Small plants can each be fertilized with one cup of fertilizer. Every pound of fertilizer will be enough to feed three small plants. Larger trees and shrubs use more fertilizer at a recommended rate of one cup for each foot of diameter.

Plant-Tone can also be worked into the top few inches of the soil in garden beds. One pound of fertilizer (3 cups) can be mixed thoroughly into every 25 square feet of garden surface soil. For container gardens, 2 cups of Plant-tone can be mixed into each cubic foot of potting mix. Flowers and vegetable plants can be fertilized in this manner once per month during the growing season.

Plant-Tone is available in sizes from 4 pounds up to 50 pounds (click this link to view Espoma Plant-Tone Organic Fertilizer on Amazon). Each pound contains about three cups worth of fertilizer. Consider how many plants you’ll be fertilizing to help pick the right size packet.

Miracle-Gro Performance Organics All Purpose Plant Nutrition Granules (9-2-7)

Miracle-Gro’s Performance Organics line includes a new all-purpose plant food that is relatively high in nitrogen. Miracle-Gro’s Organic Plant Nutrition (9-2-7) has a guaranteed minimum amount of 9% total nitrogen. This concentrated high-nitrogen blend can be used to feed plants, flowers, vegetables, and herbs.

Miracle-Gro Organic Granules are derived from Feather Meal, Soybean Meal, Nitrate of Soda, Bone Meal, Sunflower Hull Ash, Rock Phosphate, and Sulfate of Potash. It does not include beneficial bacteria or fungi.

This fertilizer comes in a convenient 2.5 pound shaker jug. The granules can simply be placed on top of the soil. One cup covers 25 square feet of soil at the recommended rate. One jug of fertilizer covers up to 240 square feet. The granules can be applied every 4 to 6 weeks.

Miracle-Gro’s Organic Granules are also available in a 1.75-pound bag option. For further details, visit this Miracle-Gro Performance Organic Granules page on Amazon.

2. Lawn Organic Fertilizer With a High Nitrogen Content (NPK)

Lawn fertilizers are formulated specifically to be high in nitrogen, as nitrogen is key for leafy green plants. Lawn fertilizer is a fast and effective way to increase the amount of nitrogen available to your lawn, trees, shrubs, and garden plants. Many lawn fertilizers have the added benefit of 0% phosphorus, making them much less likely to contribute to the pollution of local groundwater and waterways.

Here are some great high-nitrogen lawn fertilizer options:

Espoma Organic Lawn Food (9-0-0)

Espoma Organic Lawn Food (9-0-0) is a turf-grass specific fertilizer. With no phosphorus or potassium, this concentrated fertilizer is all about the nitrogen! Espoma organic lawn food has a guaranteed minimum amount of 9% total nitrogen.

Espoma’s Lawn Food is derived from Feather Meal and Poultry Manure. It also contains beneficial bacteria.

Apply this fertilizer to lawn grass and other leafy greens in springtime, preferably sometime in April through to June.

Espoma Organic Lawn Food comes in 14-pound and 28pound bags (covering 2500 square feet and 5000 square feet, respectively).

Safer Brand Lawn Restore (10-0-6)

Safer Brand’s Lawn Restore Fertilizer is an old favorite formulated specifically for turfgrass. Lawn Restore has a guaranteed minimum amount of 10% total nitrogen.

Safer Brand is currently reformulating Lawn Restore (which used to be called Ringer Lawn Restore). I haven’t had an opportunity to try the new formulation, but according to reviews posted last month the new stuff is more dusty/stinky than the old stuff. The classic product came in a 25 lb bag and covered 5000 square feet of lawn.

Worm Castings - Soil Ammendment

3. Animal Manure (Omnivore)

Animal manure from certain animals can be a good source of nitrogen for amending soil. Chicken manure is the most commonly used high-nitrogen livestock manure. Specialty animal poop like earthworm castings and bat guano is also quite common.

Composted Poultry Manure

Manure from poultry like chickens, ducks, and turkeys is high in nitrogen in comparison to other livestock manures. Poultry manure must be well composted before using it as a soil amendment. It is concentrated enough that it can easily “burn” plants if you’re not careful.

Poultry manure is available from poultry farmers or from friends with backyard chickens. Many garden centers stock composted poultry manure, and it is even sold in bags on Amazon. Be aware that different batches of manure can vary widely!

Bat Guano (9-3-1)

Poop from bats and seabirds can also be used as a high-nitrogen fertilizer. Down to Earth All-Natural Fertilizers sells OMRI-certified 9-3-1 bat guano in a 4 oz box (click to see the bat guano on Amazon).

Worm Castings (1-0-0)

Continuing on the poop theme, worm castings are a reliable nitrogen source for garden plants. Make your own in a vermicompost bin or buy pre-packaged worm castings to add to your garden soil.

4. Plant-Based Nitrogen Fertilizer Products

Leafy plants are high in nitrogen, and so are many fertilizer products made from them. Plant matter from some types of seaweed, corn, and fruit products is converted into plant-based fertilizer.

Seaweed Fertilizer (1-0-2)

Fertilizer derived from seaweed is high in nitrogen. Kelp meal is a common form of seaweed fertilizer.

Alfalfa Meal (2.5-0.5-2.5)

Alfalfa meal is a readily available nitrogen source that comes from plants. It’s also a rich source of trace elements and natural growth stimulants. Alfalfa meal is commonly used to fertilize flowering shrubs like roses.

Neem Seed Meal (6-1-2)

Neem seed meal is another plant-based source of nitrogen for the garden. This is a slow-release nitrogen fertilizer pressed from the seeds of the Neem Tree. Popular organic fertilizer brand Down to Earth offers Neem Seed Meal in a compostable 5-pound box.

Corn Gluten Meal (9-0-0)

Corn Gluten Meal is a nitrogen-rich soil amendment also known as “natural weed & feed”. In addition to providing nitrogen to soil, it also helps prevent weeds from becoming established in the spring if applied before the weed seeds germinate.

Fruit Vinegar

Diluted fruit vinegar like apple cider vinegar can be an effective high-nitrogen soil amendment for acid loving plants. Read more in this article about fertilizing your garden with apple cider vinegar.

5. Fish & Animal By-Products

Fish & animal by-products are a common source of nitrogen in generic and name brand fertilizers. Examples of materials used to add nitrogen to the soil are fish emulsion, feather meal, and blood meal.

Feather Meal (12-0-0)

Feather meal is used as an organic fertilizer because it is rich in nitrogen, contains no phosphorus, and doesn’t have some of the odor problems of other animal by-products. Feather meal tests at a whopping 12% nitrogen! That’s a lot of nitrogen in comparison to most other fertilizers (even synthetics). It’s also a slow-release food that can provide steady amounts of nitrogen to your plants.

Feather meal can be used to add nitrogen to vegetable gardens, container gardens, trees, and shrubs.

Blood Meal (12-0-0)

Blood meal is an old-fashioned fertilizer with a similar NPK to feather meal. Like other concentrated sources of nitrogen, use caution with blood meal as it can burn plants if used improperly. Always follow the manufacturer’s directions!

Fish Emulsion (5-1-1)

Fish emulsion is an organic fertilizer concentrate made from fish by-products. While it’s stinky, it can be used on all types of lawn and garden plants (although I would keep it outdoors if possible!). Fish emulsion is a manufactured version of the traditional practice of burying fish in cultivated soil.

6. Homemade Compost Enriched with Plant Matter

The following materials from around the house can also be a good source of nitrogen for plants. I like to let them compost with my yard waste first for a buffering effect rather than adding them straight into my garden.

Here are some natural sources of nitrogen to add to your compost:

  • Grass Clippings
  • Yard Waste (especially green leaves and green material)
  • Food Waste
  • Coffee Grounds
  • Seaweed
  • Cornmeal
  • Earthworm Castings (from a home worm farm)
  • Fruit Vinegars (like apple cider vinegar)
  • Manure from Herbivore Animals (rabbits, goats, et cetera)

From the natural sources of nitrogen listed above, plants are a common source of naturally-derived nitrogen. If it used to be a green and happy live plant, it’ll probably add some nitrogen to your homemade compost.

Your mix of nitrogen-rich materials will depend a lot on your surroundings. You may be able to get lots of freely-available seaweed, but have no access to herbivore manure. Whatever you have available in your region, collect it sustainably. Improving your garden soil shouldn’t come at the expense of the surrounding environment.

Sources of Nitrogen for Garden Soil

What is Nitrogen?

So what actually is nitrogen? Nitrogen is a chemical element. You’ll remember it from high-school hits such as The Periodic Table.

Nitrogen is a common element in the Universe. It’s actually the most common element in the air that makes up Earth’s atmosphere. So why pay for a high-nitrogen fertilizer!? Unfortunately for our plants, it’s not super common in the Earth’s crust (AKA our garden soil).

How Nitrogen is Added to Soil

Nitrogen particles move through our environment in a cyclical manner. It’s converted into different forms as it moves through different structures in eco-systems. Bacteria can help bring atmospheric nitrogen down into soil (especially on legume plants like clover, peas, or alfalfa). Nitrogen particles in soil can also be transported through soil by groundwater.

How Do You Add Nitrogen to Compost

Nitrogen is generally added to compost by adding leafy greens to the mix. Blades of grass, pruned leafy twigs, deciduous leaves, and other green leaves are generally high in nitrogen. Nitrogen can also be added to compost by adding coffee grounds. Here are instructions for making nitrogen-rich plant food from autumn leaves and coffee grounds.

Why Do Plants Need Nitrogen

Nitrogen is an essential nutrient for plant growth. Nitrogen particles make up a part of a plant’s many cells. Without nitrogen, a plant cannot build the cells it needs to grow and thrive. Without enough nitrogen, the plant will not be able to produce enough molecules to photosynthesize food from the sun.

Nutrient Deficiency in Plants

How Do You Balance Nitrogen in Soil?

Do a soil test before adding any fertilizer to ensure you know exactly which nutrients are out of balance. A good soil test will give specific instructions on exactly what to add to the soil to balance the nitrogen levels.

If in doubt, less is more. Don’t use more fertilizer than is absolutely necessary. It’s not good for your soil and it’s certainly not good for the surrounding ecosystem. Only add nutrients that are currently in deficit.

What are the Signs of Nitrogen Deficiency

The main sign of nitrogen deficiency is that plant leaves start to look yellow instead of green. Not all instances of yellowing leaves, however, indicate a nitrogen deficiency. The plant may simply be stressed in some other way (heat, pests, disease, et cetera). Get a soil test!

Read more about trusted natural fertilizers in this article.

Mary Jane

Mary Jane is a home gardener who loves creating healthy, welcoming spaces (indoors and out!) - About Mary Jane (https://www.homefortheharvest.com/authors/about-mary-jane-duford/)

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