Best Organic Plant Nutrients

Plants require a myriad of nutrients that naturally occur in the ground; however, it is uncommon to have that ideal combination of nutrient-rich soil consistently in your backyard.  It is often necessary to amend your soil with compost, manure, and organic fertilizers to bolster your garden soil with the right balance of nutrients.

Plants thrive on mineral nutrients to help them mature adequately, grow healthy, and to produce quality yields. Several of these nutrients are the building blocks of plants and are needed in large amounts. Let’s identify these essential nutrients and discover how to amend them into your soil effectively via organic methods.

Healthy young plant growing in the pot over blurred green garden background, outdoor day light, new life and bright

Test Your Soil

Before considering adding any amendments, it is recommended you analyze your soil to identify its pH level and nutrient content. You can obtain a test at your local garden center, which will give you a better idea of what the actual pH of your soil is. A soil test can also tell you the nutrient and chemical makeup from the soil sample, allowing you to amend your soil accordingly.

A pH scale ranges from 0 to 14, with 7.0 being neutral. pH levels that are 0 to 6.9 are acidic, and measurements in the range of 7.1 and 14.0 are more alkaline. The general goal for vegetable gardens is to have a pH of around 6.5, although there are plants whose ideal pH growing environment varies from those parameters. Different nutrients can lean either toward acidic or basic and can direct you as to what is needed to balance out the garden soil for ideal planting conditions.

All Natural Garden Soil Organic Plus

Kellogg Garden Organics

All Natural Garden Soil

**Product not available in AZ, CA, HI, NV, UT. For a comparable product in these states click here.

Six Essential Soil Nutrients  and Amendments

Six nutrients are standouts in the development of strong, healthy plants. They are all necessary and contribute in different ways to work together in the soil and assist plants in their growth and production of fruit.

There are various ways to amend these vital nutrients into your soil organically, including natural and organic liquid and granular products that can be purchased from the local garden center.


Nitrogen is represented by the “N” when we talk about “N-P-K” in fertilizers and is an essential nutrient that gives plants their green hue. Nitrogen is the first number shown on the fertilizer label and is the percentage of Nitrogen in that formulation.  It is vital to the formation of proteins within plants. A lack of this nutrient in your soil will stunt plant growth and cause the leaves to turn yellow and entire plants to turn pale green. It is crucial to maintain the proper balance of nitrogen in your garden because, conversely, too much nitrogen can hurt your plants.

How to Amend

If your soil is lacking nitrogen,  you can amend with organic fertilizer. Organic sources of nitrogen include alfalfa meal, well-decomposed compost, fish meal, poultry manure and feather meal.  Organic liquid and granular fertilizers will contain many of these ingredients.


Phosphorus is the “P” in “N-P-K” and is represented by the second number on the package label. It’s primary benefit is on root health and development. It is a necessary nutrient which aids in cell division and assists the plants’ formation of roots, flowers, and production of fruit. Soil that is lacking in phosphorus produces underdeveloped plants with stunted growth.

How to Amend

If your test results show low levels of phosphorus, you can amend it into your soil by adding bone meal, well-decomposed compost, or organic or liquid fertilizer.

Close up photo of granular fertilizer in a teaspoon.


Potassium is the “K” in the “N-P-K” and is represented by the third number on the label. Potassium helps plants grow more quickly and process water more efficiently. This essential nutrient makes plants more drought and disease resistant. A potassium deficiency results in diminished growth and weaker plants.

How to Amend

If your garden soil needs a boost of potassium, you can use wood ash, granite dust, or potassium sulfate to assist in raising potassium levels.


Magnesium is essential for plant life. It helps plants develop its green leaves, serving as the building block for chlorophyll. Without chlorophyll, plants can not carry out the crucial process of photosynthesis. It has a wide range of critical roles in many plant functions.

How to Amend

Adding Epsom salt or lime to the garden bed will improve magnesium levels in your garden bed.

Eggshells ground up in a dish.


Sulfur helps plants form chlorophyll for the crucial process of photosynthesis as well. It also is of key importance in the production of plant proteins and the activation of plant enzymes. A balanced level of Sulphur in your soil can improve the quality and yield of fruit.

How to Amend

Amend the soil with aluminum sulfate or organic granular soil acidifier. Follow the directions on the package. The amount you use should be appropriate from the plants it will serve.  Be sure you temporarily remove the mulch from around the area before applying the granules and then reapply the mulch.


Calcium is vital for the formation of roots and stems as well as new growth in plants. Calcium helps provide plants’ robust strength. Calcium also helps to bolster soil composition by maintaining soil chemical balance and enhances the penetration rate of moisture.

How to Amend

Amend your soil with limestone or gypsum to ensure that your garden soil has enough calcium. You can also crumble eggshells and mix into your soil along with well-decomposed compost to assist in calcium content.

Pouring liquid fertilizer into a cup

Organic Liquid Fertilizers vs.Organic Granular Fertilizers

Both liquid and granular fertilizers provide distinct advantages to feeding your soil and plants. They do, however, work in different ways to produce the desired results. Both can be purchased at the local garden center and can be very useful in amending your soil with all of these essential nutrients at one time.

Organic Liquid fertilizers

Organic Liquid Fertilizers can be applied easily and are absorbed quickly by plants for an instant boost in nutrients. Apply an organic liquid fertilizer to plants needing an immediate boost due to nutrient depletion. Liquid fertilizers require more frequent applications since nutrients are plant-available and are used up more quickly.

Organic Granular Fertilizers

Organic Granular Fertilizers contain essential nutrients in a solid form that require dissolving or a gradual decomposition into the soil for plants to absorb and benefit from them. The slow release nature of granular products results in nutrients that become plant-available over several months, so with only one application, two months of work is done for you. Use organic granular and liquid fertilizers together to get the best results in yield and blooms.

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