Who doesn’t love a juicy, fresh, brightly colored tomato straight from the plant? Many people dream of the moment they can sink their teeth into a tomato warmed from the sun. But, how do you know it’s going to taste good? Proper fertilization as it grows.
Let’s talk about fertilizer for tomatoes before diving into which is the best. As a tomato plant grows, it has leaves, flowers, and fruit. Plus, you have to consider disease that plagues tomatoes. So, you have to choose a fertilizer that caters to all of these.
A tomato plant that is well-fertilized will produce fruit that is brightly colored, delicious, and plump.
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A General Overview About Fertilizer for Tomatoes
Before getting too involved in choosing the best fertilizer for tomatoes, it is important that you actually understand what fertilizer is. Basically, every fertilizer for plants is made of three different nutrients: nitrogen, phosphorus, and potassium.
All three of these nutrients have different jobs. For instance, nitrogen works on the growth of the foliage, phosphorus works on the flowers, fruit, and roots, and potassium focuses on the stems.
When you buy fertilizer, you will see a number on the label, like 5-7-3. You also might see N-P-K. These numbers are the ratio of nitrogen, phosphorus, and potassium in the fertilizer. In this case, 5-7-3 means 5 percent nitrogen, 7 percent phosphorus, and 3 percent potassium.
Though all fertilizers contain these three major nutrients, they may or may not have micronutrients, which tomatoes need. These include sulfur, zinc, calcium, manganese, magnesium, and copper.
A Note on Organic Fertilizer
One note when you are thinking about choosing fertilizers for tomatoes. As we will mention, there are both organic and non-organic fertilizers. Organic, of course, is made of certified organic materials.
Generally, these fertilizers are higher in micronutrients and lower in nitrogen, phosphorus, and potassium. However, these fertilizers are less likely to damage your plants.
Most organic fertilizers also contain microscopic organisms like bacteria and fungi, which are also good for your tomatoes.
Tomato Fertilizer Types
There are three main types of tomato fertilizer: water-soluble, granular, and liquid and each of these has pros and cons that you might want to consider before choosing one over another.
Water-Soluble
The first type to explore is water-soluble fertilizer. It is a fast-acting fertilizer, and it begins to work on your tomato plants almost immediately. You can choose both organic or inorganic water-soluble fertilizers.
This type of fertilizer comes in a solid form, powder or granules, and then you mix it with water. Once it is fully dissolved, you apply it to your plants, similar to how you would water them.
Granular
Another option for tomato fertilizer is granular fertilizer. This is the easiest to apply, and you can store it anywhere. In regard to tomato plants, you can put the granules into the soil before you plant it.
If you do that, simply mix the granules into to soil with a small shovel, and then place your tomato plant or seeds into the soil.
The tomatoes might already be planted, too, but that’s okay. You can use granular fertilizer there, too. Simply sprinkle the granules around the plant and work it into the area around the roots.
When you choose granular fertilizer, you will have two choices: quick-release or slow-release.
Quick-release fertilizer gives almost immediate fertilization for the plants, and when you water the granules, they dissolve and work into the soil. A slow-release fertilizer, on the other hand, takes days or even weeks to fully break down. Some of them will work throughout the season.
Liquid
Finally, we have liquid fertilizer. This is a concentrated option that you have to dilute with water when using on your plants. You can find liquid fertilizer in both organic and non-organic options, and when it is put onto your plants, it begins to work immediately.
In addition to putting liquid fertilizer directly into the soil, you can also dilute it with water, and even use it directly on the leaves of the tomato plant for an extra boost.
Considerations for Tomato Plant Fertilizer
One of the things you have to remember when it comes to choosing a fertilizer for tomato plants is that every plant has unique growing conditions. For instance, if you have tomatoes growing in a pot and tomatoes growing in a garden, there are different conditions.
Some of the things you might want to consider is the drainage of your soil, the soil structure, the fertility that is already in the soil, and even the pH of the soil.
When you think of all of this, you might realize that it helps to have several different types of tomato fertilizer on hand, especially if you have tomatoes in different areas of your garden.
Get Your Soil Tested
One of the best ways to know what type of fertilizer is best for tomato plants is to get your soil tested. By doing this, you will know everything possible about the nutrients in your soil.

Typically, when you get a soil analysis back, it shows every major nutrient and how much is present in the soil. Then, it should also include recommendations for amendments to help bring your soil up to par.
Generally, for a small fee of less than $20, you can send your soil away and have it tested. Once you get the results, you will know what fertilizer is the best option for your tomato plants.
Fertilizing at Different Stages
When you plant tomatoes, you have to realize that they have different needs at different stages of life. For instance, when they are young, they need help becoming established, so they need a good balance of nutrients, so a 10-10-10 might be good.
Remember, there is slow-release and quick-release fertilizer, and it’s best to use slow-release options when first planting them.
After the tomatoes flower, they need more help with resisting disease and developing fruit. Thus, they need a lower amount of nitrogen but more phosphorus and potassium. You also should make sure the fertilizer you choose has calcium, or you need to add calcium to the soil.
Conclusion
As you can see, there is not really an overall “best” fertilizer for tomato plants, but now you know enough to find the “best” option for your plants.
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