Feeding tomatoes with phosphorus-potassium fertilizers during flowering and fruit set

During flowering and fruit set, tomatoes need phosphorus-potassium fertilizer. It is necessary for the unhindered outflow of organic substances formed in the leaf blades to the generative organs of the plant. Or simply to flowers and fruits.

In addition, potassium has a good effect on cell wall thickening. Thus increasing the tomato’s resistance to unfavorable conditions, including diseases. It will be more difficult for disease to penetrate the plant. And moisture will be better retained in the plant.

Potassium is precisely the element with which plants redistribute organic substances to those parts of the plant that need it most. Signs of potassium deficiency in tomatoes are the unharmonious development of the flower cluster.

This manifests itself in the fact that the order of filling the fruits in the brush is disrupted. Filling of fruits, as well as flowering in tomatoes, in a flower cluster should occur in pairs. That is, starting from the very beginning of the tomato bunch. If this does not happen, then this is a clear sign of a lack of potassium in tomatoes.

A lack of potassium in tomatoes also manifests itself when the flowers fall off at the point of their articulation with the flower raceme. With subsequent yellowing of this joint.

If you observe at least one of the above signs on your tomatoes, then you urgently need to carry out phosphorus-potassium fertilizing. Otherwise, you will most likely lose your tomato harvest.

Since all the flower clusters that the tomato will lay as it grows and develops will be guaranteed to be subject to all the negative factors described above.

That is, there will be under-laying of fruits, and in the worst case, the ovary may simply crumble during the flowering phase.

Therefore, it is necessary to feed tomatoes during flowering and fruit set with potassium monophosphate. Potassium monophosphate contains 50% phosphorus and 33% potassium. And tomatoes need phosphorus during this period of their development to improve the quality of flowering and fruit set.

Why do tomatoes need potassium?

Potassium is important not only for increasing immunity and better fruit set. It is thanks to him that your fruits become so juicy and sweet. It is potassium that is responsible not only for the taste, but also for better ripening of the fruit. Therefore, potassium is a vital mineral for tomatoes and cucumbers. Without it, the plant will have poor immunity, quickly wither, and the fruits will take a long time to ripen, or will not ripen at all. And they will become tasteless. Therefore, the very first fertilizer you should use to feed tomato bushes is potassium.

Potassium value for tomatoes

Why do you need potassium for tomatoes? The element is required for the following processes:

• rooting seedlings in a permanent place;
• facilitating adaptation to temperature changes and open ground conditions;
• strengthening immunity and disease resistance;
• improvement of metabolism;
• formation of ovaries, proper ripening of fruits.

In addition, it is common to treat blossom end rot on tomatoes with potassium fertilizers. Top rot appears from a lack of certain microelements; spraying is carried out to replenish it.

Signs of potassium deficiency in tomatoes

To better understand the consequences of a deficiency of this mineral, let’s compare a plant with the human body. Remember what a person who lacks essential vitamins looks like? First of all, this is reflected in appearance: dark circles appear under the eyes, the person looks lethargic. As for the immune system, it becomes weak. Diseases begin to affect the human body. The most banal cold becomes a real punishment.

Now about how a tomato or cucumber feels when it lacks potassium:

• General condition of the leaves: they begin to die. First the color changes, changing from yellowish to brown. If you do not notice and apply potassium fertilizers for tomatoes in time, necrosis of the leaf plates will begin. Eventually they will wither and fall off. The stem will also become weak.
• General condition of the bush: the very first sign is slow growth. Tomatoes don't grow well. Flowering is sparse and flowers are small. There are few fruit ovaries. If the soil does not contain a sufficient amount of potassium during the period of growth or fruiting, this will affect the external and taste qualities of the fruit: they will be unsweetened. Fresh. They will take a long time to ripen or will not ripen to the end. When cut, you will see greenish veins.

What do tomatoes like?

Potassium fertilizers for tomatoes help accelerate metabolism, which has a good effect on fruit set and ripening. Feeding helps the plant survive spring temperature fluctuations and protects it from pathogens. Transplantation and rooting occurs faster. At the same time, other substances, nitrogen and phosphorus, must also be present in sufficient quantities.

Video: Expert advice on fertilizing tomatoes, including potash

The tomato bush feels good when the nutrition is balanced . To do this, you should follow the sequence of feeding:

1. In the spring, before planting seedlings, you need to fertilize the soil with nitrogen so that the plants can gain green mass and be ready to set fruit.
2. Towards the end of flowering, the most important moment comes - fertilizing with potassium mixtures. If time is lost, some part of the plants may shed flowers or ovaries. At this moment, you should watch the tomatoes especially carefully in order to notice the lack of substances in time. Gardeners usually water their plots every evening. There is time to take a closer look at the foliage - if it begins to change color, then urgent action must be taken. One foliar feeding is enough for the plant to come to life.
3. In the fall, after harvesting, you need to restore the soil by digging it up with phosphorus and potassium. Fertilizers will dissolve over the winter, and in the spring it will be easy for plants to absorb nutrients.

There are different types of potash fertilizers, but not all of them are suitable for the type of soil. Knowing the characteristics of each type of mineral fertilizer, taking into account the composition of the soil - its pH, you can choose the optimal nutrition for plants (more on this in the section on types of potash fertilizers).

Potassium for plants from natural sources

To grow high-quality tomatoes and make up for the lack of nutrients, you need to understand when to apply potassium fertilizers. There is a special schedule for this, from which it is clear how and when this should be done. You can use ready-made fertilizers, which already contain all the necessary substances. But minerals are also present in other compounds. Most of them are of natural origin. These include:

• Peat. One of the most popular types of organic fertilizers. The percentage of potassium content in it is 3%. Not much, but still.
• Dust from cement. As it turns out, the building material can be used not only as an adhesive for the foundation. The main advantage of cement dust is its high potassium content (up to 30%). Light dust is highly soluble in water.
• Ash. The most popular type of organic fertilizer. It can be used in any way: add it to the hole before planting bushes in the ground, make a solution and water the plants at the root, etc. Furnace ash is the most useful for fertilizer. Potassium is contained in the combustion products of straw and firewood. The smallest amount of potassium is contained in spruce firewood (5%). Straw, remains of dry plants - 30%. Birch firewood - up to 40%.

How to recognize a lack of useful elements

Phosphorus deficiency leads to a state of stress, after which it is difficult or impossible for plants to recover. The urgent need to use phosphorus fertilizers for tomatoes occurs when:

• leaves become smaller and fall off quickly;
• the lower leaves become covered with dark spots and die off;
• bush growth slows down or stops;
• the formation of ovaries is delayed;
• the stems and veins become reddish-purple.

In addition, a lack of phosphorus leads to destruction of the roots and the plant dies. You can avoid this development of the situation if you apply phosphorus fertilizer for tomatoes in a timely manner.

Storage rules and usage features

The first thing a summer resident needs to remember is that tomatoes do not always need constant feeding. An excess of minerals also has a detrimental effect on the quality of fruits, as does a deficiency. At each stage of the growing season, the plant must be fed according to the schedule. Also, one of the main rules is to use strictly according to the permissible dosage. If the fertilizer is diluted in insufficient quantities, the tomatoes will not receive as many nutrients as they need. If you exceed the dosage, you will only harm the plant. The root system may even get burned.

But the most important rule is the storage of fertilizers. High humidity, damage to the integrity of the packaging and the ingress of foreign objects into the fertilizer will cause deterioration in properties and even a fire hazard. The main rules for storing fertilizer:

• Protect fertilizers from fire hazardous and flammable substances (sawdust, dry straw, oils, lubricants).
• If you store nitrate (calcium, potassium, etc.), treat storage with extreme caution. It explodes very easily. Potassium nitrate is especially dangerous. Keep an eye on the packaging and do not allow any pieces of fabric or cellulose to get into it.
• Do not store fertilizers on the floor or concrete. This will upset the moisture balance and the fertilizer may clump.
• Store fertilizers away from each other, in the packaging in which it was produced.
• Never mix fertilizers with one another.
• Carefully monitor the expiration date; do not use fertilizers after the expiration date. The expiration date is indicated on the packaging. Mineral ones are stored for up to 3 years, fresh organics - no more than 9 months.

Phosphorus value for tomatoes

Without this element, no plant can fully exist and each crop needs its own dose of the substance. While potassium and nitrogen affect flavor and juiciness, phosphorus helps the plant grow and produce fruit. Therefore, without it it is impossible to obtain a high-quality, abundant harvest. The purpose of this microelement is to control the metabolic processes occurring in the plant’s body. There is phosphorus - there is energy. And there is energy - there is a healthy, strong tomato bush with numerous fruits.

Fact!

The peculiarity of all phosphorus fertilizers is that they cannot overfeed plants. It is considered a passive element, which representatives of the flora consume only in the quantities they need.

By absorbing this microelement, plants:

• grow healthy, with good immunity;
• build up a powerful root system;
• bloom profusely and bear fruit;
• form viable seeds;
• form large juicy fruits.

Note!

Phosphates that get into the soil are inactive. This fact suggests another - they are not washed out of the soil, but are stored in the upper layer. Therefore, it is enough to apply some phosphorus fertilizers only once every few years.

How to properly apply potash fertilizers

Before applying fertilizer in the form you need, remember the sequence of steps. And the fact that at each stage of development and growth, tomatoes need one mineral or another. Sample list of events:

• Pre-treatment of seeds before planting. For this purpose, solutions of Zircon, Epin, Fitosporin are used. Do not use potassium fertilizers when soaking: this will slow down seed growth.

• When the plant is just starting to gain strength in a new location, use nitrogen and phosphorus. Together they will help increase green mass and strengthen the plant’s root system.
• Feeding tomatoes with potassium (whether in a greenhouse or on open ground) should be done no more than 3-4 times per season. Too frequent feeding of potassium impairs the consumer properties of the fruit. The first time is at the stage of formation of the 3rd leaf of the seedlings. The last time is when all the fruits are formed.
• Strictly observe the dosage of fertilizers.
• Watch the weather: it should be cloudy and warm. But there should be no rain or dampness.
• Suitable time: evening or early morning. The holes must be well watered so that the fertilizer does not burn the roots.
• Do not allow fertilizer to come into contact with the green mass.
• Do not use cold fertilizers.
• Rinse off any remaining residue with clean water.

Methods for applying potassium to tomatoes

The main advantage of nutritional supplements is that they can be applied however you like. The plant will still absorb all the substances, but this is only if you follow the rules and dosage. Types of application of potassium fertilizers:

• For digging into the soil: used mainly during the beginning of autumn work. During winter, potassium will remain in the soil until spring and be absorbed into it.
• When replanting plants: in this case, fertilizer is applied to the planting hole.
• During watering: in this case, potassium is applied in the form of a solution, under the root of the plant.
• Foliar feeding: spraying. This method is one of the most popular types of foliar feeding. Not only the leaves are sprayed, but also the ovaries and stems. According to reviews from summer residents, this method significantly increases the yield of tomatoes. Most often, a solution of boric acid, yeast mash or honey is used for these purposes.

What fertilizers can potassium be applied with?

You can, of course, use complex formulations to improve the result. But if you decide to feed the plant gradually, you should know which minerals combine best with potassium:

• Spring: Potassium goes well with nitrogen. Nitrogen helps increase green mass.
• Autumn: phosphorus. During the period of active growth, phosphorus is necessary for the development and strengthening of plant roots. In autumn, this element is necessary to restore the soil after harvesting fruits.

The use of potash fertilizers in different periods of growth

As already written above, the application of fertilizing is subject to several rules. Potash fertilizers should be applied when the plant is actively growing. And during the active growing season. In total, tomatoes and cucumbers are fed no more than 4 times during the season.

Main periods:

• The third leaf of the seedlings is fully formed.
• Spring: a week before planting seedlings in a permanent place.
• During flowering.
• During the formation of ovaries.
• During the period of early fruiting.

Sometimes tomatoes and cucumbers require additional feeding. This will become noticeable in the external condition of the bush and fruits. Also, if it rains outside, add additional potassium, as rainwater washes the mineral out of the soil.

Is it necessary to fertilize tomatoes strictly according to schedule?

It is PREFERABLE to follow the fertilizing schedule, but it is not necessary to strictly follow it. If you have applied everything correctly, and the bush is blooming and full of health, it does not need additional feeding.

When is emergency feeding useful?

Fertilizing tomatoes with potassium in a greenhouse or open ground requires extraordinary fertilizing only in case of acute deficiency of the mineral.

How to avoid excess potassium when fertilizing tomatoes, correct dosage

To avoid overfeeding your plant, remember only one thing: follow the dosage. Approximate instructions for preparing the solution are always written on the packaging. And don’t forget about the frequency of applying fertilizer: no more than 4 times per season.

If you feed the plant only potassium, the dosage is not difficult to maintain. But if you feed tomatoes in combination with nitrogen or phosphorus, reduce the dosage of phosphorus or nitrogen by half.

Making your own fertilizer mixtures with potassium

There is no better recipe for feeding than your own homemade recipe. If you know how to correctly combine this or that mineral, your plant will receive an explosive nutrient mixture. What can be combined:

• Potassium sulfate, phosphorus and ammonium nitrate, in a dosage of 15:20:15 grams. Mix the ingredients in 10 liters of water.
• Calimagnesia, nitroammophoska, ash and phosphorus, in a dosage of 10:10:150:20 grams. Mix the ingredients in 10 liters of water.
• Dissolve a glass of wood ash, 20 grams of double superphosphate and a liter of mullein infusion in 10 liters of water. The consumption rate per bush is up to 1.5 liters.

Rules for feeding tomatoes in open ground and greenhouses

Let's look at the basic rules, tricks and features of feeding tomatoes:

• Fertilizers should be applied at the root in the morning or evening, when the sun is not active. Or in cloudy weather.
• Before the procedure, you should water with plain water, otherwise you can burn the root system.
• Spraying the leaves should only be done in the evening after sunset or on a cloudy day.
• When spraying, the weather should be dry and windless. In this case, rain should not be expected, otherwise the precipitation will wash away the nutrients and the procedure will be useless.
• The watering rate when applying liquid fertilizers at the root is 0.5 liters per plant.
• How often to feed tomatoes? This should be done once every 1-2 weeks. You can do this more often than once every 5-7 days, but you should reduce the concentration.
• Particularly active consumption of nutrients from the soil occurs at the moment when the 3rd cluster begins to form and flowering 4 begins. During this period, it is necessary to feed potassium plants with fertilizers containing magnesium, calcium, and boron. Frequency: once every five to seven days.

Types of potash fertilizers

With a lack of potassium, the plant itself suffers first of all: the leaves and stems wither, the roots dry out. If you don’t take action in time, you won’t see a good harvest. Based on the type of origin, potash fertilizers are divided into mineral and organic. Mineral fertilizers are of chemical origin, while organic fertilizers are of natural origin. The most popular types:

• Potassium nitrate.
• Humate.
• Potassium sulfate.
• Potassium chloride, and others.

Potassium nitrate

Another name for fertilizer is potassium nitrate. Suitable for feeding tomatoes both in greenhouses and open ground. Its potassium content is approximately 46%. Other accompanying components are phosphorus and nitrogen (7 and 14% each, respectively). This type of fertilizer strengthens the plant’s immunity, protecting it from environmental influences, and stimulates the fruiting process. Potassium nitrate for tomatoes is available in the form of a white or yellowish crystalline salt. This fertilizer is suitable for use in open ground or greenhouses.

The fertilizer is used in diluted form, at a dosage of 20 grams per bucket of water.

Salt dissolves perfectly in water, has an optimal pH level and is absolutely safe for people and animals. Season: summer, during the formation of fruit ovaries. Method of application: watering at the root or foliar spraying. Nitrate will not only fertilize your tomatoes, but also protect them from rot and other diseases.

Potassium humate

This fertilizer is considered universal, as it not only contains a balanced set of minerals, but also accelerates the growth of bushes and promotes the development of fruits. The main composition of humate is humic acids, which improve the composition of the soil and increase productivity. It is used not only for fertilizing during growth, but also for soaking seeds before planting. To do this, pre-treated and disinfected seeds are placed in an aqueous solution of potassium humate for a day.

Dosage: 200 ml water and 20 ml fertilizer.

1. Frequency of application: at different stages of the growing season, approximately 3 times, with a dosage of 10 liters of water and 50 ml of humate.
2. Method of application: any. If you want to increase the fertility of the soil, do the following: dilute 500 ml of fertilizer in 10 liters of water and water the beds. Or during the autumn digging of the soil: dilute half a liter of fertilizer in a bucket of water.
3. Dosage for one-time fertilizer: dilute 50 ml in 10 liters of water.

Potassium chloride

Despite the fact that this fertilizer contains potassium, it is not worth fertilizing tomatoes with it, since chlorine deteriorates the quality of the fruits and roots. Chloride is used on other plants, such as cucumbers.

Calimagnesia

As is clear from the name, the fertilizer contains potassium and magnesium, which are selected in a balanced manner. This type of fertilizer can be used on any type of soil, even in a greenhouse. The fertilizer is most effective on sandstones. However, remember that you should not abuse it; use potassium magnesium only in case of acute deficiency of the mineral.

The dosage of fertilizer when watering at the root is to dilute no more than 30 grams in 10 liters of water. The consumption rate per hundred square meters is up to 5 liters.

Monopotassium phosphate (Monopotassium phosphate)

The main components of the fertilizer are potassium and phosphorus. Both components are useful at the early stage of ovary formation or fruiting, when you need to strengthen the root system and devote all your strength to the formation of the future harvest. Monophosphate is highly soluble in water.

Suitable types of feeding: root and foliar, in the form of spraying. Frequency of use - no more than 2 times: during fruit formation. The second application is a couple of weeks after the first.

Dosage: no more than 2 grams in 1 liter of water.

Release form: beige or light brown granules. Sometimes available in powder form. Pros of monophosphate:

• Thanks to it, future tomatoes bloom profusely and fruits form faster.
• Easily absorbed by all parts of the plant.
• Quickly decomposes in the soil without accumulating in it.
• Does not change soil acidity.

Disadvantage: due to exposure to light or moisture, it quickly loses its properties. Frequency of use of an aqueous solution: during picking (when the second true leaf is formed); a couple of weeks after landing in a permanent place; during the beginning of fruiting; a couple of weeks after the third application. Dosage: no more than 10 grams per 10 liters of water.

Potassium nitrate

Another name for fertilizer is potassium nitrate. The two active components are potassium and nitrogen. The combination is very convenient, despite the fact that these two components do not combine well. Potassium is useful for the taste of fruits and their immunity, nitrogen is useful in the early stages, when tomatoes need to quickly grow green mass.

Release form: colorless, highly soluble crystals. Tomatoes and cucumbers are fertilized in different ways: the former are watered with an aqueous solution when fruiting begins. Tomatoes are fertilized as follows:

• Treat seeds a week before planting.
• During picking seedlings.
• In the phase of appearance of the 4th leaf of the seedlings. The seedlings are watered at the root, avoiding contact with the greenery.

Potassium sulfate (Potassium sulfate)

The composition of the fertilizer is potassium, sulfur and phosphorus, in a percentage dosage of 50:46:4. The most suitable soil (be it open ground or greenhouses) is alkaline. On soil with a high acidity content, summer residents are advised not to use fertilizer. You should not use potassium sulfate constantly; it is better to replenish the mineral deficiency with it.

Fertilizer dosage for aqueous solution: 10 grams of sulfate per 10 liters of water.

Potash

Another name for fertilizer is potash. Release form: colorless crystals or granules. In addition to the 55% potassium content, potash contains magnesium and sulfur. Basically, potassium carbonate is used on acidified soil.

The optimal dosage is 20 grams of fertilizer per 1 square meter. m.

Nitroammofoska

One of the most popular potassium fertilizers for feeding plants. The main components of the composition are nitrogen, potassium and phosphorus.

Basically, fertilizer is applied during autumn and spring digging, at a dosage of 40 grams per 1 square meter. m. soil.

Thanks to the use of nitroammophoska, tomatoes acquire more stable immunity and are not affected by rot and late blight. The optimal time for processing is when transplanting young animals to a permanent place. The second application is carried out a week later.

Banana peel

It has long been known that banana peels are very useful not only for ripening tomatoes, but also as a fertilizer. So, if your bananas suddenly go bad, don’t rush to throw them away! Especially if you grow tomatoes in the country. This method of obtaining potassium for culture can be considered folk.

How to use banana peels: grind the rotted fruits together with the peel, mix with water and let it brew for a while (at least a day). Next, they are added to the holes when the young animals are transplanted to a new place. As soon as the bushes are planted, they are sprayed and watered.

This fertilizer is one of the most accessible and inexpensive, since it contains potassium, calcium, phosphorus and magnesium - that is, everything that plants need at the initial stage of development.

Complex fertilizers

These types of fertilizers contain almost the entire complex of nutrients and minerals. Why mix and measure the dosage when you can buy ready-made fertilizers? List of the most popular types:

• Nitrophoska.
• Nitroammophoska.
• Diammophos.
• Station wagon.
• Mortar.
• Kemira.
• Wood ash.

Ash

Burnt ash from plant residues or firewood is the most popular complex fertilizer. You can use it in any way you like: pour it into the holes, sprinkle it on top, or dissolve it in water. Wood ash contains a whole complex of minerals: calcium, potassium, phosphorus.

The most useful is stove ash. But keep in mind that such ash must be kept exclusively in a dry room, otherwise it will lose its properties.

The highest potassium content is in furnace ash: up to 30%. In birch it is slightly less - about 15%.

Pros of using wood ash:

• Suitable for absolutely any type of soil.
• Improves the taste of fruits.
• Repels harmful insects.

When to use:

• When transplanting plants to a permanent place (mix into the soil).
• Additional fertilization with solution or watering (in summer).
• When digging up the soil during autumn work.
• Sprinkle the soil in the greenhouse (in winter).

Kemira

Fertilizer composition in percentage ratio of potassium, nitrogen, phosphorus, sulfur and magnesium: 14:12:8:8:2. In addition, Kemira contains molybdenum, zinc, iron, selenium, boron, copper and manganese. In other words, the entire nutritional set. This fertilizer is mainly used in the form of bedding or sprinkling on beds. For example, they mix it with a small amount of soil and sprinkle the area around the beds. Afterwards, water generously.

Dosage per 1 sq. m. - about 40 grams.

Station wagon

As the name suggests, this fertilizer is universal. It contains everything that growing tomatoes need: potassium, phosphorus, nitrogen, sulfur, magnesium. The percentage ratio is 8:7:7:4:15. Also contains humic acids. There is no chlorine, which is so destructive to the root system.

Release form: granules. How to use: for 1 sq. m. it takes about 300 grams of fertilizer.

After application, the soil must be loosened and watered abundantly.

Mortar

This fertilizer is highly soluble in water and is absorbed very quickly. Ingredients: potassium, phosphorus, nitrogen, magnesium. Suitable fertilizing: root, foliar.

Dosage per 1 sq. m.: about 25 grams.

When and what to feed tomatoes with?

Throughout the growing season, tomatoes are fed three times. Feeding with nutrient solutions is combined with watering, irrigating the soil around the bush, but not the bush itself.

When preparing a nutrient solution, you should pay close attention to compliance with standards and proportions. All nutritional compositions are usually based on a bucket of water. If the plants are “fatten”, then mullein, bird droppings, and nitrogen fertilizers are excluded from fertilizing.

1. The first time feeding tomatoes is done 10 days after transplantation. For the solution, use 10 g of urea, 30 g of superphosphate and 20 g of potassium sulfate. Half a liter of solution is added to each bush. This mixture can be replaced with mullein, which is filled with water, left to brew and ferment for a week. One liter of this solution is diluted in nine liters of water.
2. The second feeding should be carried out during the period of intensive flowering. The mixture consists of 40 g of superphosphate, about 8 g of urea, 25 g of potassium sulfate.
3. The third time feeding is carried out during the period of active fruiting. To do this you will need fertilizers: 40 g of potassium sulfate, 12 g of urea, 25 g of superphosphate. When feeding the second and third times, apply 1 liter of the prepared solution under the bush.

Feeding tomatoes with a nutrient solution

To improve fruit set, accelerate ripening, increase taste and sugar content, you can add to the nutrient solution: one gram each of manganese sulfate and boric acid, 2 g of potassium permanganate and 0.6 g of copper sulfate.

The highest tomato yields are obtained when organic matter is used together with mineral fertilizers. The nutrient solution is prepared as follows: add 1 liter of mullein, 400 g of superphosphate, 200 g of urea, 10 cups of ash to a bucket of water. Mix and apply one liter under the plant, combining with watering.

Depending on growing conditions

“Own” fertilizers are suitable for fertilizing in open areas and greenhouses. Greenhouse plants require more feeding than soil plants. Tomatoes growing in a greenhouse require more nutritious and natural fertilizers.

Location on

If you are growing tomatoes in an outdoor area, fertilize them according to a schedule. You should not overuse potassium fertilizers: this will only cause harm. Use potassium only if there is an acute deficiency. It is better to use mineral and organic complex ones, such as wood ash, eggshells or banana peels.

In the greenhouse

Greenhouse crops require more care, since they are mostly deprived of fresh air and natural sun. Therefore, the most suitable fertilizers for them are organic. What you can use:

• Rotted manure. https://emtomat.ru/wp-content/uploads/2021/11/kurinyy-pomet.jpeg
• Diluted bird droppings (1 kg per 10 liters of water).

Of the inorganic ones, potassium sulfate is suitable.

At home and on the balcony

Few people grow tomatoes at home. Most often, on the balcony it’s just seedlings. In principle, it does not need additional feeding. But many summer residents sometimes feed young animals with potassium so that they can better take root in the new territory. Sulfate is most often used for this.

Instructions for use for tomatoes

It is quite difficult to check the lack of microelements in the soil.

But potassium deficiency is determined by the appearance of plants:

• The leaves dry out at the edges;
• The growth of stepchildren is activated;
• The stems become brittle;
• Barren flowers appear;
• The growth of seedlings slows down.

Gardeners will come to the rescue with a complex mineral fertilizer containing potassium and other microelements to increase tomato yields. Mineral fertilizing is carried out according to a schedule taking into account the quality of the soil, but no more than twice per season.

Gardener mistakes

The most common mistakes happen only to beginning gardeners, as they do not have the proper experience. Experienced gardeners who have been growing fruit and berry crops for many years do not make mistakes. The most common mistakes:

• Feeding with potassium is out of season. For example, when a plant is just planted in a hole, it needs nitrogen and phosphorus more than potassium.
• Fertilizing when the fruits have already finished ripening. When a potassium deficiency in fruits becomes noticeable, many rush to quickly feed the plant, trying to make up for the deficiency. However, it's already too late.
• Mixing fertilizers. Do not mix the ingredients yourself: this will only cause harm. If you don’t understand, buy ready-made compounds or use wood ash.
• Exceeding the required dosage. This way the plant will not absorb the main component and will not receive the additional one. Dilute fertilizers strictly according to the instructions.

Types of products for greenhouses and vegetable gardens

Tools by names and descriptions will help a beginner choose the most suitable ones. The best fertilizer for tomatoes is selected taking into account the properties of the soil. Potassium for plants in a greenhouse is needed in smaller quantities than in open ground. A safe way to feed tomatoes with potassium during the development of the bush and during the fruiting period is to use folk remedies. They are not as concentrated as mineral supplements and do not cause burns in case of overdose.

Foliar feeding of tomatoes with potassium is carried out by spraying; this is a quick and effective method to quickly compensate for the beginning deficiency. A number of home and industrial remedies are suitable for it, in particular, multipotassium. When looking for how to feed the bushes with potassium during the fruiting period, it is better to give preference to harmless homemade solutions.

Rules for applying phosphorus fertilizers

1. Phosphorus-containing fertilizers are first applied to the soil during the autumn digging of the site. In a few months of winter, the microelement will have time to be completely absorbed by the soil.
2. Granular fertilizers are applied only at the root, and not scattered over the entire surface of the earth. There is no point in doing this, since the granules will not dissolve in the top layer of soil.
3. If you need to achieve a quick effect, use liquid phosphorus fertilizers using soluble preparations. They can be used during crop cultivation or when digging the soil.
4. In addition to root feeding, phosphorus can be “applied” by spraying. The main thing is to dilute the fertilizer with water.
5. Phosphorus is not added to acidic soil - this will not show any result, since phosphorus is not absorbed in such soil. Before applying fertilizers, the soil is deoxidized with lime or ash.
6. Organic phosphorus fertilizers are absorbed by the soil much longer. Their effectiveness can be seen only 2-3 years after application to the soil.

Note!

Some phosphorus fertilizers cannot be applied immediately after liming. For example, superphosphate is used only two months after the soil deoxidation procedure.

Lack of phosphorus and potassium in the soil

These elements are necessary for almost any vegetable or ornamental crop, and therefore their deficiency negatively affects fruiting and flowering.

The fruits lose their sugar content, become less tasty, and the flowers become smaller and faded. In addition to taste and appearance, the yield and keeping quality of vegetables and fruits also suffer; they spoil faster and are stored worse. It is important to fertilize on time to avoid these troubles.

Potassium deficiency

The sooner a deficiency of a particular mineral is identified, the less it will affect the vital indicators of plants. Therefore, you should think about feeding in advance. Soil type can be a clue in identifying the risk area. Sandstones, super sandstones and peatlands are often deficient in potassium. The same applies to lands in floodplains.

Signs of deficiency

A lack of this element in tomatoes can be a real disaster. Even with a slight lack of it, tomatoes are delayed in growth, flowering, and fruit set. Respiratory processes and metabolism deteriorate.

Phosphorus starvation at the beginning of the growing season becomes a severe stress for plants. Restoring them is extremely difficult, and in some cases impossible.

External signs:

• small, quickly falling leaves;
• the appearance of dark spots on the lower leaves, their death;
• cessation of growth (the plant is low and bushy);
• the main stems, petioles, axils and veins of the leaves acquire a reddish-violet hue;
• dried leaves turn black.

During acute phosphorus starvation, the root system is destroyed and loses its ability to retain the above-ground mass. The plant is lodging. To prevent this, it is important to apply fertilizers to the soil in a timely manner.