If a gardener wants success producing delicious and high-yield tomatoes, they must provide the plant with the necessary nutrients. Tomatoes are the sponges of vegetable gardening, soaking up every nutrient they can get to grow big and strong.
Three nutrients, two secondary nutrients, and six micronutrients are needed to help aid your tomato plant through numerous stages of growth. This article will teach you why these nutrients are so critical without trying to sell you a product secretly. Not only that, but I’ve also compiled a list of the best fertilizers for tomatoes that will provide the nutrients they need. And don’t skip my expert tips.
Table of contents
Nitrogen
Nitrogen is the life support and energy booster of tomato plants and plays a critical role in various stages of growth.
Tomatoes need nitrogen for:
- Leaf and stem growth
- Protein synthesis
- Vegetative growth
Nitrogen is the main component of chlorophyll, the green pigment responsible for photosynthesis. This nutrient is needed because it will produce more chlorophyll, which, as a result, produces lush green leaves. Not only that, but it will help produce stem growth during the seedling and vegetative growth stages.
It is also the building block of plant protein, essential for creating enzymes that help facilitate more effective nutrient absorption, metabolism, and overall plant development during vegetative growth. It also helps shift plant energy from flower growth to fruit formation during the fruiting stage.
While nitrogen is critical for tomato seedling growth, too much will result in excessive foliage, delayed fruit production, and decreased disease immunity.
Phosphorus
Phosphorus is the architect of growth and development through all growth stages of tomato plants.
Tomatoes need phosphorus for:
- Root development
- Early plant development
- Flower and fruit formation
Phosphorus is the main nutrient used by tomato plants during the early stage of plant growth. Proper phosphorus is crucial for the tomato plant to develop from seedlings.
Phosphorus is the primary nutrient in promoting the development of roots. It helps stimulate root growth and encourages a solid and extensive root system. The root system is essential for other nutrient absorption and plant stability.
It is also involved in storing and transferring energy during all stages of growth. The energy stored and transferred encourages the synthesis of proteins like DNA. Not only that, but it promotes an abundance of flower growth and a healthy fruit set.
Potassium
Potassium is a nutrient that contributes to tomatoes’ overall well-being and resilience.
Tomatoes need potassium for:
- Disease resistance
- Water regulation
- Fruit quality
Potassium is the essential nutrient needed to help strengthen plant resistance against disease and pests. It strengthens the leaves, fruit skin, and plant walls, reducing the risk of pathogens, diseases, and infections. Not only this, but it helps tomatoes in less-than-ideal soil conditions and extreme weather.
It is also critical in regulating water and nutrient uptake. It helps maintain water balance to help prevent death during droughts or large amounts of rain. Not only that, but the plant’s ability to manage water balance also leads to its ability to ward off other environmental threats.
One of the gardeners’ favorite reasons to supply potassium to tomatoes is that it helps improve the quality and flavor of fruit. Potassium will affect the size, color, and taste of tomatoes.
Calcium
Calcium is the engineer for tomato plants, providing essential support for physical structure and contributing to growth processes.
Tomatoes need calcium for:
- Cell wall formation
- Nutrient uptake
- Effective vegetative growth
Calcium is the main secondary nutrient for plant cell wall creation and cell division. Adequate calcium ensures strong and stable cell walls are created, ultimately supporting the entire plant. Not only that, but it nourishes growing tips, roots, and shoots in the early stages of development.
It is also the most important nutrient to prevent disorders and diseases like blossom end rot. Blossom end rot is a disease where fruit becomes sunken and discolored due to a lack of calcium. Below is a video that describes a great technique for organically adding calcium to your soil.
Magnesium
Magnesium is a nutrient that assists with essential functions that help tomato plants’ overall health and vitality.
Tomatoes need magnesium for:
- Chlorophyll formation
- Nutrient uptake
- Increased stress immunity
Magnesium is a secondary nutrient essential in capturing and utilizing energy more effectively during photosynthesis. This allows seedlings and tomato plants to have healthier and more robust leaf development during vegetative growth.
It also helps transfer and store energy and facilitates the absorption and transference of nutrients more efficiently, allowing tomato plants to grow quicker and stronger.
One of the most important roles magnesium plays in the life cycle of a tomato plant is enhancing its ability to cope with environmental stresses. An adequate amount of this nutrient allows the plant to adapt and thrive in challenging conditions like extreme droughts and cold.
Iron
Iron is one of the first and most important micronutrients a tomato plant needs when growing, working in the background to support essential processes for overall health.
Tomatoes need iron for:
- Root development
- Efficient growth
- Nitrogen metabolism
While root development can naturally occur from the main and secondary nutrients, adding iron to the soil will allow your tomato plant to grow enhanced root hairs that will allow it to absorb more nutrients and water from a greater span of soil.
Not only that, but iron is critical in the metabolism of nitrogen. If you want faster growth and a stronger foundation during the seedling and vegetative stages, providing iron will allow your tomato plant to use nitrogen more efficiently.
Finally, iron is another nutrient that is important in the chlorophyll and photosynthesis process. Supplying this nutrient appropriately will increase both processes’ efficiency, resulting in more leaf and stem development.
Zinc
Zinc is the nutrient that helps tomato plants ward off diseases and stresses while contributing to better fruit productivity.
Tomatoes need zinc for :
- Fruit formation
- Stress response
- Synthesis processes
One of the most important elements of zinc is that it is involved in forming enzymes that contribute to the formation and setting of fruit. Sufficient amounts of zinc allow tomato fruit to mature properly, set, and produce higher-quality and taste.
Like other nutrients, zinc is needed to help improve stress response. Such stressors that it helps ward off against include extreme swings in temperature, pests, fungus, and other diseases that arise throughout spring, summer, and early fall.
Finally, zinc allows synthesis, including DNA creation, photosynthesis, and auxin synthesis, to occur smoothly. It helps ensure these processes occur and run smoothly in early growth stages and then assists in efficiently allowing tomato plants to process nutrients in later growth stages.
Manganese
Regarding nutrients, manganese is subtly mentioned but is crucially important to tomato plant growth and health.
Tomatoes need manganese for:
- Toxin defense
- Root development
- Photosynthesis
Manganese helps reduce toxicities in one of the most interesting times of plant growth. Manganese activates enzymes that create antioxidants that help neutralize harmful reactive oxygen species. This is critical if you want to increase the longevity and health of your plant.
It is also a critical part of cell elongation and division, allowing roots to develop, grow, and absorb more nutrients and water for longer.
Not only this, but manganese is part of almost every enzyme activation. From the efficient energy production of photosynthesis to participating in the enzymatic nitrogen reactions to reactions of carbohydrates, lipids, and amino acids.
Copper
Copper is a micronutrient that contributes to numerous biochemical processes leading to growth and plant health.
Tomatoes need copper for:
- Iron uptake
- Root development
- Enzyme activation
Providing tomatoes with iron is sometimes not enough. For iron to be absorbed and used properly, copper should be applied to gardening soil to help facilitate physiological processes more efficiently.
Copper is another micronutrient that plays a vital role in root development. Like manganese, it promotes cell elongation and division, allowing the tomato plant to absorb more water and nutrients faster.
Finally, copper is involved in different enzyme activations. One of the most important involves lignin creation, which contributes to strong cell walls. This helps with plants’ respiration and metabolism, increases their ability to detoxify harmful byproducts of physiological processes, and increases the transportation of nutrients during photosynthesis.
Molybdenum
Molybdenum is another micronutrient that most beginner gardeners have not heard of, but it contributes to plant growth, development, and health as it matures.
Tomatoes need Molybdenum for:
- Sulfur and nitrogen metabolism
- Phosphorus utilization
- Iron uptake
If you want to ensure the proper formation of sulfur and the protein building blocks of plants, then you need molybdenum. This is needed from the seedling stage through fruit formation to ensure your plant grows effectively. It is also used to facilitate better access to nitrogen for effective growth.
In addition, molybdenum is important to the metabolism of phosphorus-containing compounds, ensuring the plant can make optimal use of phosphorous. Phosphorous helps with every part of the tomato plant’s growth stage, from nutrient absorption to flower and fruit growth.
As you can tell, micronutrients play an important part in the intricate roles that nutrients have for each other. No such relationship can exhibit this more than molybdenum’s role with iron. The plant efficiently absorbs and utilizes iron for various processes and growth stages.
Boron
Boron is one of the few micronutrients gardeners know about but don’t use enough. It plays a critical role in various processes, including growth and development.
Tomatoes need Boron for:
- Flower and fruit development
- Pollination and seed development
- Calcium uptake
Boron is critical in flower growth and fruit development. It transports and distributes sugars, producing properly formed, regularly shaped, healthy, and delicious fruit.
Without boron, it would be almost impossible for plants to develop pollen tubes and germination. Proper amounts of boron are crucial for successful pollination, seed development, and fruit set.
In addition, this micronutrient is needed to help facilitate the uptake and utilization of calcium. This leads to proper cell wall formation, structural development, and transportation of other nutrients that can help skin thickness, plant quality, and fruit taste.
Expert Tip
According to the UMASS Extension: Center for Agriculture, “Maintain proper soil pH. This is important for optimum nutrient availability and health of many beneficial soil organisms.” Tomatoes thrive in acidic to neutral soil with a pH of 6.0-7.0. If the pH of the soil falls too far below or above this range, certain nutrients become less accessible, leading to deficiencies and increasing the likelihood of becoming prone to disease and even death.
You should check and test your soil before and after planting your tomatoes. More importantly, you should continuously test your soil pH while growing plants. To raise or lower your soil’s pH, apply one of the best tomato fertilizers per your plant’s specific needs. Keeping your soil pH at an appropriate range will allow your tomato plant to absorb and process nutrients effectively, leading to robust growth and fruit production.
Frequently Asked Questions
No. While there will always be slight differences in the nutrient needs of different tomato varieties, what needs to be provided is based more on the pH of the soil.
The easiest way is to do regular pH soil testing. Some other signs of nutrient deficiencies include yellow leaves, slow growth, little to no fruit, and fruit discoloration.
Regular pH soil testing is the only way to prevent nutrient imbalances. Always follow the application instructions for fertilizers when providing nutrients. And remember, over-fertilizing can create just as much imbalance as not fertilizing.
Learn More About Tomatoes
While providing nutrients is crucial for high-yield and delicious fruit, you can check out my articles below to learn more about how you can produce better tomatoes this year!
How to Grow Tomatoes from Seed
Take Away
Understanding the significance of the different types of nutrients is critical to the plant’s overall health and ultimately provides quality fruit. The plant will almost always grow strongly and quickly by providing nutrients in each stage. It will also have abundant flowers, providing quality and tasty fruit.
