Best Organic Tomato Fertilizers for 2023

Tomato plants consume large amounts of nutrients from the soil. If you don’t supplement, the plants will run out of resources and your plants will suffer. Make sure you meet their needs by using the best organic tomato fertilizers.

Our Favorite
best organic tomato fertilizer

Espoma Organic Tomato-Tone with Calcium

We have had excellent results. In our opinion, this is the best organic tomato fertilizer on the market. Since using it, we’ve had no more issues with blossom end rot thanks to the added calcium. The flavor of our tomatoes seems to have improved with regular use of this fertilizer. If you’re looking for an all-natural organic fertilizer to enhance tomato production, look no further.



  • All natural ingredients
  • Contains calcium and micronutrients
  • Slow release, won’t burn plants
  • Made in USA


  • Not water soluble

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Using the Best Organic Tomato Fertilizers

It is every gardener’s dream to have plump, juicy tomatoes on their plants. To make this dream come true, you need to provide your plants with the ideal conditions. One of the most important factors is providing the right nutrients at the right time. Make sure you’re using the best organic tomato fertilizers whether you’re growing in the ground, in pots or in grow bags.

Plants that receive the proper nutrients are more resistant to disease and produce more flowers, ultimately resulting in more fruit. To encourage strong, healthy growth, you need good soil. Start with a soil mix that contains compost and/or worm castings. Just before planting, mix some slow-release granular fertilizer into the soil. Then use a water-soluble fertilizer every two weeks during the growing season. You can read more about this below.

Summary of the Best Organic Tomato Fertilizers

Our FavoriteEspoma Organic Tomato-Tone

Best GranularBurpee Organic Tomato Food

Water SolubleMiracle-gro Performance Organics

Liquid FertilizerNeptune’s Harvest Tomato Fertilizer

Fertilizer SpikesJobe’s Organic Fertilizer Spikes


How To Choose The Best Organic Tomato Fertilizers

What do those numbers mean?

If you look at the fertilizer package, you will see a row of three numbers. The first number is nitrogen (N), the second is phosphorus (P), and the third is potassium (K). The numbers indicate the levels and proportions of each of these major nutrients in the fertilizer.

Early Season: Vegetative stage

When tomato plants are in a vegetative state prior to setting fruit, the most desirable nutrient is nitrogen. That doesn’t mean the plant won’t benefit from some phosphorus and potassium, just that tomato plants require more nitrogen during this stage. During this time when tomato plants are in a vegetative state, using a balanced nutrient with the same three numbers (5-5-5 or 10-10-10) is never a wrong answer.

Mid/Late Season: Fruiting stage

Large amounts of phosphorus and potassium are used in fruit production. This applies to all fruit bearing vegetables, especially tomatoes. When the tomato plants begin to flower, it’s time to start thinking about a fertilizer that contains phosphorus and potassium in larger proportions than nitrogen. In addition, the potassium index should be equal to or higher than the phosphorus index (3-4-6). Using an organic fertilizer that’s highest in nitrogen during the fruiting stage will result in plants with lush green foliage but lacking in flower and fruit production.


The best organic tomato fertilizers should also contain some or all of the following micronutrients. It’s things like calcium that can help prevent blossom end rot. Magnesium helps plants absorb nitrogen and phosphorus more efficiently. Sulfur can improve the taste of tomatoes.

Combination of the best organic tomato fertilizers

Organic fertilizers used in combination can be a great way to get the perfect nutrient ratios. For instance, amend your soil pre-planting with a granular fertilizer, such as the Burpee Organic, which has a ration of 3-6-4. This will slowly release the nutrients for several months. Then use a fertilizer, like Espoma organic, with a ratio of 3-4-6 when watering. Using this combination gives an overall ratio of 6-10-10. Having phosphorus and potassium higher than nitrogen is the perfect combination for flowering and producing large, plump tomatoes.

Our Picks: The Best Organic Tomato Fertilizers

Burpee Organic Tomato Fertilizer

Best Granular
best organic tomato fertilizer burpee

Using slow-release granules, like these, before planting is an excellent way to boost tomato growth. It’s easy to use and works well with plants grown in the ground or containers by feeding your plants for up to 3 months.



  • Long lasting
  • Great nutrient ratio for fruit growth
  • Easy to use
  • Rarely needs to be reapplied


  • Not good for starting seeds

Miracle-Gro Performance Organics

Best Water Soluble
best organic fertilizer for tomatoes miracle-gro

If you’re looking for a great water-soluble organic fertilizer that can be mixed in a watering can, this is it. The high potassium ratio really boosts tomato production. Use this fertilizer once your plants start flowering.

TypeWater soluble powder


  • Water soluble
  • Instantly feeds
  • Easy to store
  • Includes micronutrients


  • Needs to be applied frequently

Neptune’s Harvest Tomato Fertilizer

Best Liquid Fertilizer
best organic fish fertilizer for tomatoes

Neptunes Harvest produces many great natural fish fertilizers so we were happy to see this one specifically targeted at tomato growth. Just add a little of this to your watering can to feed once every two weeks.



  • Easy to use
  • Contains potassium and potash
  • Readily absorbed by plants
  • Good nutrient ratio


  • Only makes 36 gallons
  • Strong smell

Jobe’s Organics Fertilizer Spikes

Best Liquid Fertilizer
best organic fertilizer spikes for tomatoes

Some gardeners prefer a one and done solution. These plant spikes fit the bill. Stick them in the ground and the slow-release will feed your plants with every rain or watering.

TypeSlow release solid


  • Simply to use
  • No mixing required
  • Low odor
  • Includes mycorrhizae for root growth


  • Not targeted specifically for tomatoes

Final Thoughts

If we could only have one product from our list of the best organic tomato fertilizers, it would be the Espoma Organic. However, we found that using the Espoma in combination with the Burpee granules, gave us excellent results. If you’re looking for something more cost effective that doesn’t require any mixing, consider Jobe’s fertilizer spikes which aren’t specifically targeted at tomatoes but produce good results. The best bang for the buck is the Miracle-Gro organic which is cost effective and goes a long way while providing higher than average improvements in yield.

You used the best seed starting trays and the best seed starting mix to start your tomato seeds, don’t let all that hard work go to waste. Be sure and use a top-quality fertilizer to ensure you get the bountiful harvest that you deserve.

FAQ: Best Organic Tomato Fertilizers

How often should I fertilize tomatoes organically?

This depends on the type of fertilizer you are using. When using water-soluble nutrients, start watering once when you first plant tomatoes. Then continue feeding every two weeks. Granular and slow-acting fertilizers can be added periodically, some last up to 3 months.

What do you feed tomatoes when fruiting?

During the fruiting phase, use an organic fertilizer for tomatoes that is rich in phosphorus and potassium. These nutrients will be in high demand from your tomato plants. Remember not to introduce too much nitrogen at this point, it should be the smallest of the three numbers (e.g. 3-4-6)

Is 10-10-10 a good fertilizer for tomatoes?

Organic fertilizers for tomatoes with this ratio are best used in the vegetative phase before fruit set. Use fertilizer with less nitrogen during the fruiting phase.

What nutrients do tomatoes need most?

The most important nutrients are nitrogen, phosphorus, and potassium. Tomato plants also require trace or micronutrients such as calcium, potash, magnesium, and sulfur.

What happens to tomato plants with too much fertilizer?

Tomato plants that get too much nitrogen will have lush leaves but will be lacking flowers or fruit. If you give too much fertilizer overall, you may notice “burning” of the leaves. Yellowing and browning begin at the tips of the leaves. Even the best organic tomato fertilizers can cause nutrient burns if you use them too often.

What does nitrogen deficiency in tomatoes look like?

Nitrogen is a mobile nutrient, meaning it can be redistributed within the plant. When tomato plants aren’t getting enough nitrogen, the leaves begin to turn yellow. This yellowing usually begins with the largest, oldest, and lowest leaves. It is the plant’s attempt to reclaim nitrogen in order to continue new growth.

What are the signs of overwatering tomato plants?

Signs and symptoms of overwatering are often confused with nitrogen deficiency. If the tomato suffers from overwatering, the entire plant will be pale green and begin to turn yellow. As mentioned above, yellowing due to low nitrogen levels is first noticed on the oldest or lowest lying leaves.

Are coffee grounds good for tomato plants?

In a word, no. Gardening “hacks” like this one are usually invented by some TikTok’er trying to get views. The idea behind this is that coffee grounds are acidic and help acidify the soil (lower the pH) and add nutrients. Although slightly acidic soil improves nutrient uptake, there is no evidence that tomatoes benefit from adding coffee grounds to the soil. In fact, the caffeine in coffee grounds can be harmful to plant development.

Is Epsom salt a fertilizer for tomatoes?

Espom salt is magnesium sulfate. If your plants are magnesium deficient (yellow leaves with green veins), they may benefit from some Epsom salts added during watering. However, magnesium deficiency in the soil is rare. It is not recommended to use it without testing the soil to confirm the deficit. Excess magnesium can be very harmful to plants.


I hope this review has been helpful in finding the best organic tomato fertilizers. While you’re here, take a look at our collection of heirloom tomato seeds.

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