What is the Best Liquid Fertilizer for Tomatoes?

Many home gardeners measure their gardening success by their tomato harvest. Dreaming of that successful harvest may have you wondering, what is the best liquid fertilizer for tomatoes?

Best Liquid Fertilizer for Tomatoes

There are several liquid fertilizers for tomato plants on the market. Sometimes it can seem a little overwhelming on which one to choose. After years of growing tomatoes, I consider only a handful to be tried and true, making them the best liquid fertilizers for tomatoes. 

• Fish Emulsion
• Compost Tea
• Fox Farm Tiger Bloom
• Swamp Water

A Closer Look at the Best Liquid Fertilizer for Tomatoes

As a general rule, organic liquid fertilizers are pretty gentle. They can be used on a weekly basis to encourage healthy growth. Since they are a water-soluble fertilizer, nutrient availability is immediate and easily absorbed by your tomato plants. Let’s take a closer look at some of the best liquid fertilizer for tomatoes.  

Fish Emulsion for Tomatoes

Fish emulsion is one of the best liquid fertilizers for tomatoes, It is especially helpful in the early stages when growth is needed. It is an organic liquid fertilizer that has an npk ratio of 5-1-1. Fish emulsion also has a lot of nutrients.

When to use Fish Emulsion for Tomatoes

Since it has a higher nitrogen content, a good time to use fish emulsion is on young tomato seedlings. It can be used once they have their first sets of true leaves. As well as transplanting time, and early in the growing season.

How to use Fish Emulsion for Tomato Plants

Fish emulsion can be used by diluting it into a gallon of water to use as a foliar spray. You can also use it to water your tomato plants at the base of the plant, watering the root zone.   

Fox Farm Tiger Bloom- The Best Liquid Fertilizer for Tomatoes

Throughout the growing season, tomato plants require a different n-p-k ratio.  Once they have grown a bit, the best liquid fertilizer for tomatoes is one with higher phosporus to give you a healthy fruit set.

Tiger Bloom is designed to encourage an abundant fruit and flower set. With its npk ratio of 2-8-4 it’s perfect for tomatoes ready to flower. You can start using Tiger Bloom at the first signs of flowering all the up through harvesting. A popular choice for a complete set of the best liquid fertilizer for tomatoes from start to finish is the Fox Farm Trio with Cal-Mag.

Compost Tea

Not only can you amend your soil with compost, you can also use it to make compost tea. It is one of the best liquid fertilizer for tomatoes and your garden in general.  

Adding compost and using compost tea will add beneficial microbes, which help break down organic matter to increase nutrient uptake.  Beneficial microbes also help build soil structure which provides easier access to nutrients and water.  Compost tea is a clear win-win!

How to Use and Make Compost Tea

Compost tea can be used on a weekly basis as a foliar spray or to water your tomatoes at the soil level. Making compost tea is easy. Simply take a five gallon bucket and submerge some compost or worm castings in water. Next, add a little backstrap molasses to feed the microbes and a bubbler for oxygen. Let this sit and bubble for 48 hours. You can then water your plants with all the goodness of compost tea!

Swamp Water

If you want a completely free way to fertilize your garden consider making a barrel of swamp water. The idea behind swamp water comes from Korean Natural Farming practices.  

It is one of the best liquid fertilizer for tomatoes and the garden in general. After making my first barrel a couple years ago, I never turned back! You can always find a barrel of swamp water in my garden.

How to Make Homemade Swamp Water

To make swamp water you can take any natural ingredients like plant matter, manure, and even blood from butchering livestock (aka blood meal) and submerge it into a 55 gallon drum full of water. I often add the clippings of tomato plants that I have pruned, comfrey, banana peels, and any other veggie scraps I have.

Once you have a large collection of materials in your barrel of water, put a top on it and let it rot down for a couple of months. Once everything is well broken down, all of the nutrients that were locked inside of all that organic matter are now in your swamp water.

Strain it and use it as a foliar spray or to water your plants on a weekly basis.  It is an excellent way to fertilize your garden for free. I will warn you though, it doesn’t smell the greatest!

Tips for Using Liquid Fertilizer on Tomato Plants 

When watering your tomato plants with a liquid fertilizer, the best method is to dampen the soil first. Dampened soil will absorb the liquid fertilizer easier. This makes it easier for nutrients to reach your plant roots.  It will be less prone to running off the top of dry soil.  

Additionally, it is recommended to use the best liquid fertilizer for tomatoes as a foliar spray either first thing in the morning or in the evening. Using it at the right time, will make it less likely to burn your plants.

Be sure to properly dilute liquid concentrate fertilizers. Mix it according to the directions to avoid burning your plants. 

Best Organic Fertilizers for Tomato Plants

Even if you are using the best liquid fertilizer for tomatoes, you may find that your tomato plants will benefit from other organic garden amendments. Let’s take a look at the best organic fertilizers for tomato plants, shall we? 

Bone Meal for Tomato Plants

Bone meal is an excellent source of organic phosphorus, which is essential for blossom production. It will give you more blossoms and more fruit. Phosporus also encourages strong roots.

Fertilizing with bone meal will also increase calcium uptake for your tomato plants. This will keep blossom end rot at bay, giving you high fruit quality.  

When and How to use Bone Meal for Tomato Plants

Bone meal can be used to amend your soil prior to planting or at transplanting time. Side dressing your tomato plants with this phosphorus-rich fertilizer will give your tomato plants a fruit setting boost. Doing a soil test at the beginning of the growing season is always a good idea to see what your garden soil actually needs.  

Blood Meal for Healthy Growth

Using blood meal as an organic garden amendment will provide a water-soluble source of nitrogen to your plants and garden soil. Blood meal is particularly high in nitrogen, which is good for growing healthy tomatoes. 

When and How to use Blood Meal For Healthy Tomatoes

Amending your garden soil with blood meal at the beginning of the growing season is a great way to give your plants a boost of nitrogen. This will get them off to a good start. You can also side dress your plants with blood meal if they are lacking that lush green foliage.

Remember to always do a soil test to see what your soil needs. Adding too much nitrogen and not enough phosporus to tomatoes will produce large plants with little blooms, leading to less fruit. 

Worm Castings for Organic Nutrients

Worm castings are a great organic tomato fertilizer. They are full of nutrients, beneficial bacteria, and microbes. Adding worm castings improves the soil structure. This helps your tomato plants take up essential nutrients.

A handful of worm castings can be used at planting time or as a side dress throughout the growing season.  You simply cannot go wrong by using worm castings for plant nutrition and soil building. 

​Using Epsom Salts for Healthy Tomatoes

Epsom salt is an excellent source of magnesium, making it a great addition to your tomato fertilizer routine. Magnesium helps tomato plants absorb calcium more efficiently. This makes your tomatoes less likely to have blossom end rot. 

Epsom salts can be used at transplanting time or even as a weekly foliar spray. I like to use a table spoon dissolved into a gallon of water as a foliar spray until you have a good fruit set on your tomato plants. 

My Secret Organic Tomato Fertilizer Combo

Every year at tomato transplanting time, you can give your young plants the best start by mixing up a combination of organic soil amendments that your tomatoes will love.  My secret, organic tomato fertilizer combo is full of natural ingredients. It will set your young plants up for a fantastic growing season.  

In a bucket, mix up:

• 4 cups of worm castings
• 1 cup of Epsom salts
• 1 cup of egg shells that have been broken down in a food processor or blender.  

The worm castings will provide the essential nutrients, beneficial nutrients, and microbes. While the Epsom salts will provide magnesium to help tomato plants absorb the calcium provided by the broken down egg shells.  

It’s a winning combination to use a transplanting time.  Simply give each tomato plant a handful into the transplant hole. 

Add Compost for Healthy Tomatoes

Amending your garden soil with compost at the beginning of every growing season is always a good idea to help build fertile soil.  Adding composted organic material will help build soil structure, provide nutrients, add beneficial bacteria and microbes, retain moisture, and reduce erosion.  You can also use compost as a side dress throughout the growing season to feed your tomato plants. 

Tomato-Tone Organic Fertilizer

This organic fertilizer is specially formulated to grow plump, juicy tomatoes.  It has a rich blend of the finest organic ingredients and is also enhanced with beneficial microbes.

Tomato-Tone has an n-p-k ratio of 3-4-6 and also contains 8% calcium to help prevent blossom end rot. It is an easy, all in one, slow-release formula for growing flavorful tomatoes. 

Best Synthetic Fertilizers for Tomato Plants

While I do try to use mostly organic tomato fertilizer, sometimes my sandy garden soil requires something a little heavier at the beginning of the growing season. After all, the goal is to grow food. If using a little synthetic fertilizer gets you there, go for it.

Just be cautious not to destroy the soil in the process. It is easy to overuse this type of fertilizer, which can harm your soil.  Fertilizers can also run off into our waterways, so it needs to be used responsibly.

For best results when using this kind of fertilizer, less is best. I have found that using these two synthetic fertilizers once a year gives my garden the boost in essential nutrients it needs for a nice bumper crop of tomatoes.  

Ferti-Lome Gardeners Special

An excellent all-purpose plant food that contains both fast and slow-release fertilizer is Ferti-Lome Gardeners Special. It has an npk ratio of 11-15-11.

I like Ferti-Lome Gardeners Special because it contains the necessary trace elements to help produce a bountiful harvest. These elements need to be replenished since they are quickly depleted by heavy feeders, like tomato plants.

Ferti-Lome Tomato and Vegetable Food

Using Ferti-Lome Tomato and Vegetable Food provides essential nutrients for better growth and better flowering, leading to a bigger harvest. For synthetic, I think it is the best tomato fertilizer. It has an n-p-k ratio of 11-22-8, giving you the higher phosporus content needed for an abundant tomato harvest.

Main Types of Fertilizers for Tomatoes

• Granular Fertilizers for Tomato Plants- Slow-release fertilizer of necessary nutrients, breaking down overtime. Dry fertilizer doesn’t need to be applied as often as liquid fertilizers and are less likely to wash away in the rain. Granular forms of fertilizer are also known for their ease of use, especially in a large garden.
• Water-Soluble Fertilizer for Tomato Plants- Strong reputation for giving plants a quick boost of additional nutrients, but washes away quickly. They can be used to water with or as a foliar spray. 
• Synthetic Fertilizers for Tomato Plants- Commercial fertilizers give quick growth and high production. However, overuse can deplete soil of microorganisms and beneficial bacteria leading to unbalanced, depleted soil.  If you choose this route, use sparingly. It is easy to use too much fertilizer when going synthetic. Synthetic fertilizers are often granular fertilizers. 

Essential Nutrients for Growing Tomatoes

Along with nitrogen, potassium, and phosporus, tomatoes also require calcium and magnesium. Growing lots of delicious tomatoes will also require healthy soil amended with composted organic matter.  Tomato plants are heavy feeders, needing the best liquid fertilizer for tomatoes. They also require regular maintenance, like pruning and trellising.

How to Fertilize Tomato Plants Throughout the Growing Season

During the growing season and each stage of growth, your tomato plants will require different levels of essential nutrients at different times.  Don’t let it confuse you though.

A general rule is to start out with a fertilizer that has a higher nitrogen than phosporus and potassium. Once you get to the flowering stage, you’ll want to have a fertilizer that is higher in phosporus to promote flower and fruit production. I like to provide a good source of calcium and magnesium from transplant to fruiting. 

Before Planting Do a Soil Test

At the beginning of every growing season, before you amend your soil, do a soil test to see exactly what your soil needs.  It can be as simple as the at home soil test kit that measures your soil pH and npk ratio of your garden soil.  

If you’d like to take it a step further, you can do a more comprehensive soil test like the Redmond Soil Test Kit.  It not only measures the soil pH and npk ratio but the micronutrients in your garden soil as well.

All you need to do is purchase the kit, collect your soil sample, and mail it back to Redmond.  The analysis will come complete with instructions and recommendations on what the best products are to amend your garden soil with. 

How Much Tomato Fertilizer Do Tomatoes Need?

To grow juicy, flavorful tomatoes, your tomato plants need a steady supply of nitrogen, phosporus, potassium, calcium, and magnesium, as well as other key micronutrients.  The most important thing to remember is to do a soil test to see what your soil actually needs.  

Amending your soil with high quality compost, a handful of my homemade organic tomato fertilizer, and using a weekly foliar spray of fish emulsion and Epsom salts can often be enough to grow a bountiful tomato harvest.  

As you can see, there are a ton of options when it comes to fertilizing your tomato plants. Find a method that works for you, keep it simple, and be sure not to over fertilize.  

How Long Should I Fertilize my Tomato Plants?

Once you have harvested your first tomatoes off of your mature plants, you can stop fertilizing your tomatoes.  From here, enjoy the best harvest of all those juicy tomatoes!

What is the Best Liquid Fertilizer for Tomatoes?

From fish emulsion, compost teas, swamp water, to Fox Farm Tiger Bloom, there are several great options when it comes to the best liquid fertilizer for tomatoes depending on what stage of the growing season you are in. Do your research and pick the best option for you and your growing style!

You may also enjoy reading How To Save Tomato Seeds Without Fermenting Guide and downloading my Free Printable Companion Planting Chart

Happy Homesteading & Tomato Growing,

Jenny @ The GrahamStead Family Farm

Jenny and her family have been homesteading for over 20 years. They are currently farming on their 10 acre Florida farm, that they built from the ground up, 8 years ago, growing 100% of their meat and a lot of their vegetables. From their small herd of Aberdeen Angus Cattle, Pastured Poultry, Sheep, and seasonal pigs, they are able to raise enough meat for the family while selling extra to the community. All the while, striving to butcher at home, as much as possible, and use the bits and pieces of their harvest by preserving food, making bone broth, and (Jenny’s favorite) tanning all kinds of hides!