Tomatoes are popular container plants and specialty fertilizer is available at big box stores and even small convenience stores.
Tomato feed is a lower nitrogen fertilizer that is designed to help improve flowering and fruiting of the tomato plants. The fertilizer would be suitable for other plants that need fruiting and flowering support. It is not recommended for plants with large leaves or those that do not fruit like lettuce and squash.
Tomato fertilizers often also contain added minerals like calcium and magnesium to support flowering and fruiting and to help protect the plants from disease.
Tomato Tone, a very popular tomato fertilizer, has an NPK of 3-4-6. The first number represents the nitrogen and it is the lowest humber here, it also has 8% calcium.
A soil test is the best way to choose what products you should use in your garden, but as a general rule tomato fertilizer will support the growth of tomatoes, peppers, cucumbers, eggplant, strawberries and beans.
Choose a different fertilizer for plants with big leaves and acid loving plants. For example tomato fertilizer would not be great for lettuce.
What Is In Tomato Fertilizer?
Tomato fertilizer is fertilizer that is specially formulated to help gardeners get a big crop of large tomatoes from their plants. Tomato fertilizer generally has a lower nitrogen number and a higher potassium number and often contains added calcium.
These products can contain minerals that support tomatoes as well. Some products contain blood meal, kelp or potash to supply calcium, magnesium and sulfur.
I usually see liquid and granular fertilizer options that are marketed as tomato fertilizer.
Liquid fertilizers will release all their available nutrients when applied making it suitable for use when the plant is starting to flower and set fruit. Each manufacturer has different recommendations for application, so be sure to read the packaging thoroughly.
When applying properly diluted liquid fertilizer keep it away from the stem and leaves to prevent burning.
Granular fertilizer is designed to release its nutrients over time, Tomato Tone, a popular granular fertilizer that will break down into your soil over the course of several waterings.
Granular fertilizer can be applied less frequently and will break down over time.
It is possible to turn a granular fertilizer into a liquid fertilizer by soaking the granules in hot water.
Can I use tomato fertilizer on other vegetables?
Tomato fertilizer is generally a fertilizer with a lower level of nitrogen and often contain calcium. These are special ratios and nutrients that help support normal growth in tomato plants.
The higher level of potassium and phosphorus support the production of more flowers and fruit.
These fertilizers can be used to support other garden vegetables that flower and produce fruit.
Cucumbers and peppers are plants that often do well with tomato fertilizer, but they may need nitrogen support when the plants are becoming established if you are growing from seed.
Some plants need more nitrogen and will not thrive with tomato fertilizer.
Plants that are valuable for their leaves like lettuce or plants that put out big leaves like watermelon and squash generally need a higher nitrogen content.
Here are some examples of common garden vegetables and if they will benefit from a tomato fertilizer:
| Plant | Tomato Fertilizer? | Notes |
| Cucumbers | Yes | Be sure not to include additional nitrogen |
| Flowers | Yes | Add to improve budding, may need additional nitrogen support |
| Blueberries | Maybe | Test soil, it should be acidic. Between 4.5 and 5.1. Requires additional Nitrogen to support leaves. |
| Peppers | Yes | Very similar fertilizer needs |
| Strawberries | Yes | Both enjoy potash |
| Watermelon | No | Prefers a more balanced fertilizer. Consider a 10-10-10 |
| Lettuce | No | Prefers Nitrogen rich fertilizer |
Cucumbers need a similar NPK, one where the N is lower than the P and the K, peppers are similar, but lettuce, watermelon and squash need a balanced fertilizer.
There are many ways to add nitrogen to the soil; compost, blood meal, animal manure or a urea based fertilizer will all support plants that need more nitrogen.
When choosing a fertilizer be sure to start with a soil test, pay attention to your soil PH as some plants have a narrow tolerance range for PH.
Fertilizers may not list the PH as visibly as the NPK ratio and they may alter your soil PH.
Soil PH monitors like this one on Amazon are inexpensive and easy to use.
Tomato fertilizers can improve your yields with peppers, cucumbers, eggplant and tomatoes when applied regularly during the growing season.
Can I Use Tomorite on Other Plants?
Tomorite has an NPK ratio of 4-3-8 and would be suitable to use on cucumbers, peppers, strawberries and other flowering and fruiting plants.
Tomorite contains more potassium than any other nutrient and it also contains seaweed which contains important nutrients and minerals.
Tomatoes grow better with sufficient calcium and magnesium in the soil and the seaweed provides these nutrients.
Tomorite is a liquid fertilizer meaning that it will release all its nutrients to the plants when it is applied rather than slowly over weeks.
It is recommended that this fertilizer be applied when tomatoes or other plants start to fruit, this is a boost to improve the yield of the plant.
Start your seeds in enriched potting soil or add a more balanced fertilizer when getting the plants established in a greenhouse or outdoors.
Apply these fertilizers when your vegetable plant is flowering and fruiting, usually after the first 2 to 3 weeks of growth.
You may also wait until you start to see fruit appear on your peppers, strawberries, cucumbers and eggplant.
Can I Use Tomato Fertilizer on Grass?
Tomato fertilizer is designed to support fruiting and flowering plants and it will not be beneficial for grass which prefers a higher nitrogen fertilizer.
Tomato fertilizer is higher in potassium and phosphorus.
Nitrogen is what supports a green lawn all season long, and nitrogen is quick to leave the soil. This is why gardeners often fertilize grass regularly to keep it green and lush.
Now, if your soil tests indicate that your soil is poor in potassium and phosphorus a tomato fertilizer could be helpful when establishing grass, but it is not the most cost effective solution for this purpose.
Consider adding potash or gypsum for potassium and kelp for phosphorus. These will remain in the soil longer, help improve the texture and support your soil heath longer than a liquid or granular commercial fertilizer.
These soil additions may also be more affordable.
What Is the Best Fertilizer for Tomatoes?
Potassium rich fertilizer with added calcium and magnesium is generally recommended for tomatoes. Tomato fertilizers should also contain nitrogen and phosphorus.
Tomatoes grow best in rich soil that provides these nutrients.
The best way to assess your fertilizer needs is with a soil test. Nitrogen leaves the soil quickly so even though tomatoes do not require a large amount of nitrogen you may still need to amend your soil to get your plants well established.
Choose a fertilizer that will build your soil over time, blood meal, composted manure, alfalfa meal and gypsum may all be recommended by a good soil test.
Even in healthy soil using a product specifically designed for tomato growth once the plant is established may improve flowering and fruiting.
Gardeners report larger fruit with the use of products like Tomato Tone and Great Big Tomatoes.
Composting Tomatoes for Fertilizer
Tomatoes can be used to feed other plants. The best way to use damaged, green or overgrowth of tomatoes is to compost them and apply the compost in your next growing season.
You can also allow the tomatoes to begin rotting and add them to a hole for pumpkins, watermelons or fruit trees.
This technique for planting in poor soil requires a deep hole, a little time and some uncomposted nitrogen rich fill. Tomatoes can be used here.
You can use excess tomatoes as soil builder just as you would with kitchen scraps.
If your tomatoes suffered from blight or insect damage do not compost them or add them back to the garden in any way. Treating blight requires the removal of the damaged plants and fruits and treating with a fungicide.
Remove these tomatoes far from your garden to prevent the airborne spores from infecting healthy plants or neighbors gardens.
Tomato Fertilizer for Other Plants
While tomato fertilizer is not optimal for all your garden produce, it is a fairly mild fertilizer that will not cause harm if used all over your garden.
Be aware that plants with large leaves and lettuces will likely need additional nitrogen to promote proper growth.
Be sure to perform a soil test to help guide your product choice when planning your garden.
You are likely to get the best deals and the best results by using individual products to address your soil needs and applying specialty fertilizers only at the peak of the growing season for your vegetables.
When growing fruiting and flowering plants consider:
Alfalfa meal
Blood meal
Poultry manure
Kelp
Compost
Gypsum
Potash
Lime or Eggshells
All of these soil additions can improve the soil texture and add potassium and phosphorus to the soil.
Kelp and gypsum will also add calcium which can help protect the roots of plants like tomatoes, peppers and cucumbers.
