5 Of The [BEST NATURAL] Tomato Fertilizers!

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Have you ever tried using a natural or organic tomato fertilizer to grow your tomato plants?

Let’s face it. Tomatoes are undoubtedly the most popular plant grown in many home vegetable gardens.

man planting seedings using natural tomato fertilizersPin

They are hardy plants and can grow in almost every “hardy” zone. However, tomatoes are heavy feeders and need a lot of nutrients.

One of the most frequent questions that dominate tomato discussions is:

  • “What is the ideal natural tomato fertilizer“?
  • “What is the Best Tomato Fertilizer“?
  • “Can I use a complete fertilizer on my tomatoes”?

Tomatoes may need organic fertilizer at certain stages of their growth depending on the plant nutrients available in the soil.



In this article, we will focus on good tomato fertilizer using natural methods and products. Some call these “homemade tomato fertilizers.”

What Are The Nutrients In My Tomato Soil?

To know the best fertilizer or the right natural fertilizer for tomato plants, you’ll need to know the nutrients in your soil first. Some like to use an organic tomato fertilizer like the one at Amazon.

If your soil has a high nitrogen content, you might not be required to add more nitrogen to it.

However, it’s unlikely you will have too much nitrogen content in your potting soil as it leaches easily from the soil mix.

Perform a soil test to determine the nutrient levels in your soil.

There are home test kits for the soil you can use to determine soil pH and macronutrient levels.

Conversely, you can take your soil to the state cooperative extension service for testing.

Nutrients Needed For Different Stages of Tomato Plant Growth

After knowing the nutrient levels in your garden or pot soil, you’ll need to know the different nutrients needed at different stages of the tomato plant growth cycle.

This will help you know the type of homemade fertilizer for tomatoes to apply at each stage.

Remember, tomato plants are heavy feeders and fertilizing tomatoes requires a complete fertilizer package for their needs at different periods during the growing season.

During transplanting, add more phosphorous using bone meal fertilizer to ensure rapid and strong root development. This will help your tomato plant to grow optimally and faster.

Once your tomatoes are established with a good root system, you can raise the potassium level to ensure vigorous growth of the plants and the establishment of fruits.

Wood ash from the fireplace can be an ideal source of potassium. Work it well into the soil.

At this stage, avoid high nitrogen levels on your tomato plants (try blood meal instead), as it might cause excessive foliage growth at the expense of fruit.

Now, with that in mind, we can analyze.

Organic Natural Tomato Fertilizer And When To Use Them

1. Compost

A high-quality compost pile will produce rich, pure organic matter loaded with essential nutrients and beneficial microbes.

That’s why we recommend that you have a simple compost bin to help build rich soil.

Compost has all the basic nutrients, both macronutrients and micronutrients that are usually absent in synthetic fertilizers.

Homemade Compost releases the nutrients gradually, thereby providing long-lasting nutrition.

It helps fertilize tomatoes and helps the soil retain nutrients and water, neutralizes the soil, and adds beneficial microorganisms to the soil.

Add a significant amount into the bottom of each hole during transplanting and side-dress each tomato several times during the growing season.

During the growing season, make a compost tea with some humic acid and apply it regularly.

2. Epsom Salt

Tomatoes use lots of magnesium while growing, and Epsom salt helps provide tomatoes with the necessary magnesium.

You’ll see more blooms, stronger plants, more fruit production, deeper green color, and taster, sweeter tomatoes.

Planting Tomato Seedlings – When planting a new tomato plant, place about 1 tablespoon of Epsom salt in the bottom of the hole.

Make sure to cover the Epsom salt with a thin layer of dirt before placing the tomato seedling in the hole.

Related: Read our article on blossom end rot and Epsom salts.

3. Fish Emulsion

This is another natural tomato fertilizer that gives them an extra boost at transplanting and during the growing season.

It’s rich in phosphorous, nitrogen, potassium, and other important minerals such as magnesium, calcium (which helps prevent blossom-end rot), and sulfur.

Fish emulsion is available as a concentrated water-soluble liquid fertilizer made by blending various parts of the fish, including bones.

Natural tomato fertilizers from Organic Tomato Fertilizer to Fish Emulsion FertilizerPin

Unlike compost, the major nutrients in the fish emulsion are available to the plants immediately.

When applying, read the instructions on the package, and foliar spray your plants every few weeks.

You can also boost your seedling by drenching the root zone with the fish fertilizer for plants diluted in water.

NOTE: Another organic tomato fertilizer from the ocean is kelp meal. Apply Kelp fertilizers after plants begin to flower.

Kelp may stimulate flowering due to it containing gibberellin-type compounds.

Early in the growing cycle, tomatoes need to put energy into growing new roots and leaves.

Related: Tips On Deep Watering Tomatoes

4. Organic Cottonseed Meal

This ideal natural fertilizer for tomatoes can be added as an organic soil amendment when transplanting seedlings. Cottonseed meal is rich in potassium, nitrogen, and phosphorus in a ratio of 6-2-1.

The high nitrogen level supports foliage growth during the early stage of plant growth.

The nutrients in cottonseed meals are not available to the plants immediately; they are released slowly and last for close to four months.

It contains essential elements such as magnesium, calcium, copper, sulfur, and other trace elements such as zinc and manganese.

When purchasing this organic tomato fertilizer option, choose the products that are only labeled Certified Organic.

Some cottonseed meals might contain pesticide residuals that are restricted.

banner for favorite pests controlPin

Related: Best Natural Pest Control Solutions For The Home and Garden

5. Used Coffee Grounds

Green waste, aka used coffee grounds, can enrich the soil in your garden and provide various benefits for plants like tomatoes. Coffee grounds contain nitrogen, phosphorus, and potassium that promote healthy plant growth.

A study conducted using used coffee grounds from Starbucks found the used coffee grounds contained about:

  • 2.28% nitrogen
  • .6% potassium
  • .06% phosphorous

They also measured some copper and a trace of magnesium. When applied as a soil amendment, the grounds immediately provided some nutrients and released some gradually. 

Acid-loving plants such as tomatoes can benefit from mixing coffee grinds into the soil.

Coffee Grounds Soil Drench

Used Coffee Grounds and tea are good low-level nitrogen sources, along with potassium and phosphorus. 

To use as a soil drench like a “manure tea,” mix 5-6 cups of coffee grounds in a 5-gallon bucket of water. Pour 1-2 cups of the coffee-water mixture around the tomato plant.

6. Animal Manure

Animal manure or cow manure is a classic plant food and the best manure for tomatoes, but before application, you need to keep several things in mind.

Never use pet manures; cat and dog manures are highly toxic, dangerous to humans, and full of pathogens.

Only use manure from vegetarian animals such as horses and cattle. (Don’t use chicken manure).

Manure must be aged or composted before use as it can be too strong for tomato plants.

Apply manure at the time of planting your tomato seedlings.

7. Vegetable-Based Organic Fertilizers

Some of the best vegetable fertilizers include:

Alfalfa Meal – This can be found as rabbit food or hay bales. Alfalfa meal is a complete NPK fertilizer and is packed with loads of micronutrients and helpful hormones.

Tomatoes planted in compost and dressed with alfalfa pellets thrive very well. Mulch tomatoes to help reduce moisture loss from evaporation.

Seaweed – If you live near the beach, try feeding your tomato plants seaweed; they might be low in NPK but have over 60 trace elements crucial for fruit formation.

You’ll also find liquid seaweed fertilizers on the market, like the kelp meal mentioned above.

8. Fertilize With Black Strap Molasses

Here is an interesting organic formula.

TomatoCasual.com shares: Molasses has a 1-0-5 NPK ratio and contains potash, sulfur, and trace minerals. Molasses, for years, has been used as a nutritional soil amendment, a carbohydrate source to feed and stimulate organisms, and a chelating agent.

Molasses can come in 2 forms. One is in liquid form that can simply be bought at the store. The second is dry molasses sprayed on grain residue and dried. But regardless of which form you use, blackstrap molasses is the type of molasses with the highest level of sulfur, iron, and micronutrients, which is excellent for man and soil. via TomatoCasual.com

Related: Details on using Molasses for Plant Fertilizer.

The Florida Online Journal suggests using urea and blackstrap molasses mixtures to control root-knot nematodes.

This video shows you how.

The Bottom Line

Naturally fertilizing tomatoes is not new to the world of growing tomatoes. For many years, gardeners relied on synthetic fertilizers, believing that chemical fertilizers were better than organic fertilizers.

However, most have realized that our grandparents’ organic gardening methods created an ideal and natural solution to fertilizing tomatoes.

Using the best organic fertilizer for tomatoes can provide sustainable and eco-friendly gardening practices and the necessary nutrients for robust and flavorful tomato crops.

Try any of the above natural fertilizer options to maximize your tomato yield, but always test.

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