The 9 Best Tomato Fertilizers of 2023
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Get ready for delicious, juicy, and beautiful tomatoes
The Spruce / Marcus Millan
Some plants do fine in your garden without a lot of added nutrients. But tomatoes are what are called "heavy feeders." They have a lot of growing and a lot of producing to do in just a few short months, and they need the proper nutrients to fuel all that growth. Enter fertilizers for tomatoes. Whether you choose organic or synthetic, fertilizers do basically the same thing—they provide the proper amount of essential nutrients that the soil might lack.
Garden expert Erin Hynes, a former horticulture extension agent and author of numerous garden books, says, "Tomato plants will certainly grow without fertilizer of some sort, but they will likely be smaller, less healthy, and produce far fewer actual tomatoes. And especially if you are planting them in a garden plot where garden plants have been depleting the soil of nutrients for many years, fertilizer for tomatoes is almost essential."
To help you find the best options for your plants, we researched dozens of tomato fertilizers and evaluated products based on the NPK ratio (the ratio of nitrogen, phosphorus, and potassium), other essential nutrients, longevity, effectiveness, ease of use, and value,
Best Overall: Black Kow Cow Manure 0.5-0.5-0.5
What We Like
Improves soil texture
Contains helpful microbes
Can be used in planters, in-ground, raised beds
Suitable for a variety of plants
What We Don't Like
Heavy bag
Composted manure has long been the gold standard of fertilizers for a wide variety of plants, and is perfect for tomatoes. It's an environmentally friendly source of balanced fertilizer and unlike many composted manure retailers, Black Kow lists its nutrient percentages (.5-.5.-.5). But don't let those low numbers fool you. This fertilizer is a multi-tasking powerhouse. Manure is actually a soil amendment, and it improves the texture of the soil, making it looser, better draining in wet conditions, and more water-retentive in dry conditions. It also contains valuable micronutrients and attracts earthworms, which further fertilize the soil with their droppings.
The old-fashioned way to access manure for fertilizer was to find a manure source, transport it, and compost it for several months to a year (putting fresh manure on soil can burn plants with too much nitrogen. It must set and decompose for several months before being used on plants). Black Kow takes out all the steps and packages it in tidy bags for relatively easy transport (just keep in mind that this bag will be heavy). We also like that it can be used on different types of plants, as well as in raised garden beds, in-ground, and in planters. This composted manure can be applied directly into the soil at the start of the season, using the instructions and amounts listed on the packaging.
Price at time of publish: $16
NPK Ratio: .5-.5-.5 | Type: Soil-like texture
Best Budget: Burpee Organic Tomato & Vegetable Granular Plant Food
What We Like
Also works for other vegetables
Available in a small amount so you buy only what you need
Contains beneficial microbes and micronutrients
What We Don't Like
Not a great budget option for larger tomato gardens
When you are growing just a few tomato plants, you don't want to spend a lot on fertilizer. We like this organic granular fertilizer because it is available in a small amount for a reasonable price. Plus, it is specially formulated to be lower-nitrogen so your tomato plants aren't all foliage and few tomatoes. Since it's organic, it contains lots of goodies most synthetic fertilizers don't: several different types of microbes, as well as secondary and micronutrients like calcium, magnesium, sulfur, iron, and manganese. We also like that you can use it on different types of vegetables, so none of it will go to waste.
Just follow package directions and sprinkle it around the base of your tomato plants at planting time. It's ideal for tomatoes planted in the ground, for seedlings, and for plants in patio containers and pots. We like that it lasts for three months (when tomato plants typically mature) because it is not recommended that you fertilize them as they approach harvest time. If you have a larger tomato garden, this might not be the best budget option, but we still think it's an excellent choice to consider overall.
Price at time of publish: $9
NPK Ratio: 3-6-4 | Type: Granules
Best with Calcium: Espoma Organic Tomato-Tone TO8 Vegetable Food
What We Like
Organic
Slow-release
100 percent organic with no fillers or sludges
No mixing required
What We Don't Like
Expensive
If your soil is deficient in calcium, it can cause a tomato disease called blossom end rot. The bottom of the developing tomato gets an annoying brown soft spot on the bottom that ruins it. A leading cause of blossom end rot is erratic moisture (letting the plant consistently dry out between waterings)—while the tomato plant can continue to grow, a lack of consistent moisture can prevent calcium from reaching the plant.
If even, consistent watering doesn't prevent your tomatoes from developing blossom end rot, a lack of calcium in the soil may be the culprit. (Soil testing is the only way to be sure.) In that case, you'll want a good tomato fertilizer specially formulated with calcium, like Espoma Organic Tomato Tone. Along with 8 percent calcium, it includes beneficial microbes as well as the three basic plant nutrients, nitrogen, phosphorus, and potassium. We also like that it is 100 percent organic and can be directly applied, with no mixing required. Although it is more expensive than some other options on this list, we think it's a great choice, especially if your soil lacks calcium.
Price at time of publish: $20
NPK Ratio: 3-4-6 | Type: Granular
Best Liquid Fertilizer: Miracle-Gro LiquaFeed Liquid Tomato, Fruits and Vegetables Plant Food Refills (2-Pack)
What We Like
Convenient formula
Works for other vegetables as well
Can water plants at the same time
Works quickly
What We Don't Like
Recommended for use with the Miracle-Gro LiquaFeed feeder, sold separately
Need to apply more often
As easy to apply as watering your plants, the Miracle-Grow LiquaFeed Plant Food can be applied every 1-2 weeks to give your tomatoes and other plants a "quick snack." Each bottle of this 2-pack can cover up to 400 square feet. You will need to purchase the Miracle-Gro LiquaFeed Feeder to apply the liquid (instead of mixing it with water in a watering can or using a plant sprayer that you already own). But you can still water your plants at the same time since the feeder is connected to a garden hose.
We also appreciate that the nutrients in a liquid are absorbed both by the leaves and the roots more quickly than granular or other slower-release fertilizers. Although this option has to be applied more often and requires the additional purchase of the Miracle-Gro sprayer, we think it's a great choice for those who love a simple, fast-acting application, as well as accomplishing two tasks at once.
Price at time of publish: $13
Type: Liquid | NPK: 9-4-9
Best Spikes: Jobe's Organics Tomato Fertilizer Spikes
What We Like
Convenient spike form
Low nitrogen formulation
No mixing required
Low risk of burning plants
What We Don't Like
Don't specify if/when you need to replenish with new spikes
Nothing could be easier than Jobe's Spike Tomato Fertilizer. All you do is insert two spikes around the base of your tomato plants at planting time for months of a slow, steady delivery of nutrients as the spike slowly dissolves. No measuring, no mixing, no fuss, and almost no risk of overfertilizing or burning your plants. Unfortunately, Jobe's doesn't specify how long the plant spikes last, so we have to operate under the assumption that like other plant spikes, it will provide enough nourishment for a few months.
You'll pay a little more per plant for the convenience of Jobe's Spike Tomato Fertilizer, but your initial outlay will be small and could save you money in the long run since you are less likely to waste the fertilizer. The 18-count package will fertilize nine plants. If you want to store it for another year, put it in a zip-seal plastic bag so the spikes don't absorb moisture over time and get gummy.
Price at time of publish: $10
NPK Ratio: 6-18-6 | Type: Stick
The Best Tomato Cages for Your Garden
Best Smart-Release: Osmocote Smart-Release Plant Food, Flower & Vegetable
What We Like
Lasts up to 4 months
Can prevent fertilizer burn
Easy to apply
Can be used on other plants
What We Don't Like
Expensive for the size
Osmocote, which has been around for decades, has a "smart release" formulation, meaning that nutrients are released as soil temperatures change in the spring. It releases nutrients to your tomatoes exactly when they need it, over time, rather than all at once as with liquid fertilizers. That timed release also makes it harder to burn your plants with nitrogen overfertilization, another danger with liquid fertilizers and even with some slow-release fertilizers. Osmocote claims that you can apply three times more than recommended and still not experience fertilizer burn. This margin of error is helpful for gardeners who are unsure of how much fertilizer to apply.
This formulation of Osmocote lasts four months, and since you should discontinue any fertilizing with tomatoes once they are close to harvest, it's very much a set-it-and-forget-it fertilizer application. You can buy Osmocote in a variety of sizes and use it on nearly any plant, including houseplants. It's so convenient and effective that you may want to invest in the larger 8-pound bag to use throughout your landscape.
Price at time of publish: $12
NPK Ratio: 14-14-14 | Type: Granules
Best Granular: Miracle-Gro Shake 'n Feed All Purpose Plant Food
What We Like
Convenient application
Contains micronutrients
No expiration date
What We Don't Like
Pricey
Slightly high in nitrogen
Miracle-Gro Shake 'n Feed All-Purpose Plant Food works for a variety of plants, including tomatoes. The nitrogen level is a little on the high side, but we liked that it contains excellent natural additives so that it does more than just supply just nitrogen, phosphorous, and potassium. Those quality ingredients include kelp, earthworm castings, feather meal, and bone meal, which help soil texture and create good conditions for helpful microbial efficiency.
This fertilizer is easy to apply, contained in a moisture-tight shaker so humidity doesn't affect the texture. It also doesn't have an expiration date, like some fertilizers, so you can store it for next season. Just shake it onto the soil and water well. It feeds up to three months, which is the perfect timing for tomatoes since you should not continue to fertilize tomato plants as they near harvest time.
Price at time of publish: $20
NPK Ratio: 12-4-8 | Type: Granular
Best Slow-Release: FoxFarm Happy Frog Tomato & Vegetable Fertilizer
What We Like
Certified organic
Rich assortment of micronutrients and microbes
Last longer than other formulas
What We Don't Like
Need to apply more than once
Has a strong smell
Happy Frog Tomato & Vegetable Fertilizer is naturally slow-release, made of organic materials that break down over time. It contains the Big Three nutrients (nitrogen, phosphorous, and potassium) but also contains calcium, which will prevent blossom end rot in soils that may lack adequate calcium content.
This fertilizer is specifically formulated for use on all veggies and many other plants. It's recommended that Happy Frog be applied monthly throughout the growing season, which is more often than with some other slow-release fertilizers (also less convenient and may cost more), However, it is easy to do—just lightly shake it into the top inch or so of soil and then water thoroughly.
We also like that Happy Frog is Organic Materials Review Institute listed, which means that it meets the standards set by the U.S. Department of Agriculture National Organic Program standards.
Price at time of publish: $24
NPK Ratio: 5-7-3 | Type: Coarse powder
Final Verdict
Black Kow Cow Manure 0.5-0.5-0.5 is our top choice for a tomato fertilizer because it supplies the three basic nutrients tomatoes need (nitrogen, phosphorus, and potassium) and naturally contains micronutrients. Plus, since it's a soil amendment, it has the added benefit of improving the overall texture of the soil, to make it better for your plants. If you just need enough fertilizer for a few plants, we like the Burpee Organic Tomato & Vegetable Granular Plant Food. This 4-pound bag is easy to apply and provides everything your tomatoes need to thrive, including different types of micronutrients.
What to Look for in a Fertilize for Tomatoes
NPK
Most garden fertilizers provide the "Big Three" of plant nutrients--nitrogen (N), phosphorous (P), and potassium (K). You'll see them represented, always in the same order, in terms of ratios. A 10-15-10 fertilizer is 10 percent nitrogen, 15 percent phosphorous, and 10 percent potassium.
Each nutrient performs a different role, says garden expert Erin Hynes, a former horticulture extension agent and author of numerous garden books. Nitrogen fuels green leafy growth. Phosphorous assures strong roots. And potassium helps in a variety of ways, including flowering and overall plant health.
With tomatoes, look for fertilizers that have a relatively low first number (for nitrogen), because that nutrient will stimulate lots of green leafy growth and giant plants with relatively few actual tomato fruits.
Formula
You can choose the right type of formula and application method to suit your soil and plant's needs and your personal preferences.
Commercial-manufactured synthetic formulas are highly concentrated and water-soluble, so they work quickly to give your tomato plants the nutrients they need. However, you will need to make sure you follow the application guidelines to avoid causing fertilizer burn. The Osmocote Smart-Release Plant Food is a good choice if you are afraid of overfertilizing since it is designed to break down slowly.
Organic formulas contain valuable microorganisms to help feed your plants while improving the soil conditions. They derive their ingredients from natural sources including manure, kelp meal, bone meal and blood meal, alfalfa meal, as well as other plant, animal, or mineral sources. While they tend to take longer to work, they can also last for longer periods of time. Our Best with Calcium option, the Espoma Organic Tomato-Tone Vegetable Food is 100 percent organic and helps prevent blossom end rot.
Liquid fertilizers need to be diluted before application, but they supply nutrition to your plants immediately for quick results. However, you will need to reapply them more frequently. Our Best Liquid Ferlizer pick is the Miracle-Gro LiquaFeed Plant Food because it is easy to apply and is fast-acting.
Granular fertilizers are either mixed into the soil or through a method known as "top dressing" (spreading or sprinkling the granules over the soil's surface). You can choose between quick-release or slow-release formulas: Quick-release formulas live up to their name, dissolving into the soil in just a few weeks. Slow-release formulas can last as much as an entire growing season, as they contain microbes that gradually break down the fertilizer.
You can also find fertilizers in other forms including dust, powder, and in convenient, easy-to-use spikes, like the Jobe's Organics Tomato Fertilizer Spikes.
Soil
Hynes says, "Tomatoes are heavy feeders, so they need a steady supply of macro and micronutrients. If your soil is naturally fertile, it might be enough to add organic matter like compost to feed soil organisms. But if your soil nutrients are locked up because the pH is too high or low, or if your soil has a low supply of a necessary nutrient, you want to apply a fertilizer that will address the specific problem." Conduct a soil pH test if you are growing tomatoes in the ground for the first time, and are not sure of the quality of your soil and what it needs.
Frequently Asked Questions
What is the best tomato fertilizer ratio?
A wide variety of fertilizers will work well for tomatoes, but as a general rule, if you are only using one type of fertilizer, look for so-called "balanced fertilizers," the ones with labels that list the nutrients (nitrogen-phosphorus-potassium) in the same proportion, for example, 8-8-8 or 10-10-10.
Some gardeners, especially those who know they have nitrogen-rich soil and have worked in manure or another high-nitrogen soil amendment into the soil, prefer to opt for one with that first number (nitrogen) that is lower, for example, 5-10-5 or 5-10-10.
Do fertilizers work with all tomato plants?
All types of tomato plants need ample nutrients and fertilizers are one way to make sure they produce well. No matter what type of tomatoes they are, they need similar nutrients.
Which is better granular or liquid fertilizers?
"Remember the story of the tortoise and the hare? Granular fertilizers — especially slow-release ones—give your tomatoes a slow, steady supply of nutrients for slow, steady growth," Hynes says.
"Traditional liquid fertilizers are the hares that give tomatoes a quick blast that doesn’t last, so you have to fertilize more often—especially if you water often or get heavy rain. An exception are liquid biofertilizers, which contain microorganisms, not dissolved nutrients."
Can you over-fertilize tomato plants?
"Absolutely," Hynes says. "If you apply too much of a dry, fast-release fertilizer, you can burn the roots and wipe out soil microbes in the area. But the more common scenario is using a fertilizer with too much nitrogen, which makes the plant grow big and leafy but produce few or no tomatoes."
Why Trust The Spruce?
This list was researched and written by Veronica Lorson Fowler, a freelance writer for The Spruce. She is a Master Gardener and the author of several garden books as well as hundreds of magazine and website articles on gardening.
To put together this list of best tomato fertilizers, Fowler considered factors such as effectiveness, price, nutrients, duration, and ease of use. Fowler also consulted garden expert Erin Hynes, author of numerous outdoor living and garden books.
Read Next: The 9 Best Fertilizers of 2023
