Mineral Review

What plants love potassium chloride?

Potassium chloride (potassium chloride) is one of the most popular basic fertilizers in private households. This is due to the availability and speed of migration in the soil compared to other potash plants, which makes it possible to promptly feed annuals with potassium chloride during the season. However, the same speed of migration and the presence of chlorine ions, which are contraindicated for many garden crops, require the use of potassium chloride with caution. Potassium chloride can be used to feed plants that do not like chlorine, such as potatoes, carrots, pumpkins and others, you just need to know how and when.

Properties of potassium chloride

Potassium chloride (KCl) is a concentrated mineral supplement whose main component is potassium. Depending on the manufacturing method and classification, it may contain 52% – 99% potassium. It looks like granules or crystals of pink, white, gray, brown shade. It is obtained by reacting potassium hydroxide with hydrochloric acid under laboratory production conditions. In production, the raw materials are potassium-containing salts.
Potassium chloride is used in agricultural technology, pharmacology, and the food industry.

What is potassium chloride used for?

On chernozems, nitrogen-containing and phosphorus fertilizers can be reduced or not used at all, but potassium fertilizers are necessary because of their ability to:
– increase the “immunity” of plants and prevent diseases;
– increase the frost resistance of perennial plants;
– help plants tolerate temperature changes;
– reduce the likelihood of plant dehydration;
– positively influence the formation of fruits, especially tubers;
– improve product quality – taste, size, color;
– increase the shelf life of the crop. Potash fertilizing is necessary on any type of soil. On depleted soils, potassium chloride fertilizer is applied together with nitrogen-phosphorus fertilizers or as part of complex fertilizers. On heavy, fertile soils it is applied as an independent fertilizer.
When using, strict dosages must be observed. Despite all the benefits, excessive use can lead to a decrease in soil fertility due to the presence of sodium impurities in potassium chloride and negatively affect plant growth due to the chlorine content in it.
You can protect plants from the influence of chlorine compounds by timely application of a mineral supplement. In agricultural technology, this type of fertilizer is usually used in the off-season, during periods of heavy rain. Chlorine is washed away by rain, and potassium remains in the form of granules and crystals, which contributes to a longer action of the beneficial microelement.

The use of potassium chloride for plant nutrition is necessary in the following cases:

For urgent foliar feeding by spraying with a 1-2% solution in the presence of signs of potassium starvation (see below) – here it’s chlorine, not chlorine, you need to save;
On heavy soils, when filling the soil with mulch in the spring at the rate of 25-35 g per square meter. m. depending on soil fertility. Light permeable soils are filled with potassium sulfate, and potassium chloride is not recommended for filling them at all;
In order to prepare perennials for winter – by warmth after harvesting 10 g/sq. m on medium and heavy soils, 20 g/sq. m on the lungs. In the latter case, up to 50% of the active substance will be lost;
For seasonal feeding of chlorine-tolerant vegetables and fruits – according to the rules of agricultural technology for a given species and variety. You definitely cannot quickly feed cucumbers, tomatoes, potatoes, all berries, legumes and salads with potassium chloride;
When planting “potash gluttons” – potatoes, carrots. The planting hole is dug 7-8 cm deeper than usual, 2-3 pinches (a third of a matchbox) of potassium chloride – seeds or granules – are added there and sprinkled with earth. While the plant develops, the chlorine will leave, and most of the potassium will remain at the roots.

Hunger strike and overfeeding

It is necessary to use potassium chloride for emergency feeding if the signs of acute potassium starvation are clearly visible on the lower old leaves: – The leaves are shriveled, their edges are curled.
– Brown spots appear between the veins.
– In severe cases, the wrinkled edges of the leaves turn brown as a continuous border and dry out. In case of mild potassium starvation (seedlings do not sit well in the ground, young stems are twisted, pale, tillering is weak), it is best to feed the plants with potassium magnesia. Potassium chloride often causes overfeeding of weakened plants, as if a person who had been starving for a long time immediately overate to the point of nausea. In perennials, overfeeding with potassium is most often expressed in diseases of the roots and freezing of the buds in winter, but in annuals it is immediately visible: the stems lie down and rot at the root collar. In this case, it is possible to save at least part of the crop by immediately stopping all fertilizing, reducing watering to a minimum and removing some of the fruitful shoots with unripe fruits.

Application of potassium chloride for different plants

All root vegetables respond well to potassium – sugar beets, carrots, potatoes. Grapes, tobacco, cereals, cucumbers, and tomatoes love this microelement. However, chlorine can harm plants. Grapes, tobacco, potatoes, beans, and all berry bushes respond negatively to large amounts of chlorine.
Beetroot, corn, and cereals are more resistant to chlorine. If plants react poorly to potassium chloride due to the chlorine content in it, it is recommended to replace this fertilizer with potassium-free chlorine fertilizers, for example, potassium magnesium or potassium sulfate. To neutralize the effects of chlorine, fertilizing is carried out in the fall so that this element is washed away by precipitation and groundwater by the beginning of the growing season. Potassium has a longer effect and will be completely decomposed in the soil by spring.
In spring, chlorine-containing fertilizers can be used in damp areas, during rains and snow melting, after heavy watering. The spring application of potassium chloride is carried out on light sandy and sandy loam soils, and the autumn application on medium and heavy soils.

Norms for applying potassium chloride fertilizer

– Potassium chloride is usually added during digging in the fall, the norm according to the instructions is 100 g – 200 g/10 m².
– In spring, the norm decreases to 25 g – 50 g/10 m².
During the growing season, potassium fertilizers are also used on depleted soils.
So that potassium reaches the root system of plants faster, and chlorine does not harm the development of crops, potassium chloride is added as a solution.
Due to its high hygroscopicity and good solubility, preparing a solution of potassium chloride is not difficult. To do this you will need potassium fertilizer 30 g/10 l of water. Application of a mineral supplement is more effective if carried out several times per season than a single application of a large volume.


Potatoes are extremely sensitive to chlorine. This element reduces the starch content in tubers. Potassium chloride is applied to potatoes once per calendar year – in the fall after digging at the rate of 100 g/10 m².
On light soils, it is better to abandon the chlorine-containing additive and replace it with potassium magnesium or cement dust.


Tomatoes do not tolerate chlorine well. Therefore, when applying potassium chloride fertilizer for tomatoes, use the digging method in the fall at 100 g/10 m² so that the chlorine is washed out of the soil by spring.
For spring, starting fertilizing, chlorine-containing fertilizing is replaced with potassium sulfate.


For cucumbers, the addition of potassium is of great importance; its deficiency has a bad effect on the taste of the vegetable and the volume of the harvest. However, cucumbers cannot tolerate an excess of this mineral supplement. Before fertilizing all cucumber plantings with potassium chloride, it is necessary to carry out selective, test fertilizing.
Select two or three plants and apply a base solution of 0,5 liters per plant. After a few days, see if the growth of the lashes has improved and if the color of the leaves has changed. If the plants are in order, you can feed the rest of the plantings.
In greenhouse conditions, it is enough to apply a liquid additive 2 times during the growing season; in open ground, the application increases to 3–5 times. Liquid fertilizing is applied to well-watered soil or after rain. Autumn fertilizing for plowing and starting spring fertilizer for cucumbers are not required.


It is not recommended to apply potassium chloride to grapes, since this delicate plant does not tolerate chlorine. However, grapes need potassium supplements to increase frost resistance, better ripening of berries and vine growth.
Grapes are usually fertilized with potassium sulfate.

Fruit trees

Fruit trees, especially apple trees, require potassium feeding and tolerate chlorine-containing fertilizers well. On average, 150 g of potassium chloride is applied to a fruit tree. The volume of fertilizing can be adjusted depending on the type of soil. For chernozem, the dose can be reduced to 120 g, and for light soils increased to 180 g.
They apply granules when loosening the moist soil, but it is better to make a solution and water the trees during fruiting. In conclusion, it is worth noting that potassium preparations have a positive effect on all plants. But, due to the fact that most of these products contain a chloride component, its use can be harmful to some plants and soils. It is recommended to fertilize the soil with potassium chloride only in the fall and in strictly limited quantities, since chlorine is harmful to many garden crops. Long-term use of the drug negatively affects the condition of the soil – it can become acidic. In addition, potassium chloride contributes to the accumulation of salts in the soil.


  • Price list
  • Nitrogen fertilizers
    • Urea
    • Ammonium nitrate
    • Urea-ammonium mixture (UAN)
    • Ammonia water
    • Nitroammophoska
    • Liquid complex fertilizers
    • Fertilizer mixture “STIMUL”
    • Organo-mineral fertilizer “Agrolife”
    • Double Superphosphate
    • Ammophos
    • Caustic (caustic soda)
    • Sodium hypochlorite
    • Soda ash
    • Potassium monophosphate
    • Boric acid

    This is a very controversial fertilizer. On the one hand, it is often mentioned in recommendations on agricultural practices for various crops, on the other hand, it has many limitations. Let’s find out whether it is worth using potassium chloride in the garden

    If the soil in your garden is low in potassium, do not expect abundant flowering or even a small fruit harvest. It is this nutrient that is responsible for the plant being able to form flowers and fruits. Potassium deficiency weakens plant immunity and resistance to stress caused by cold, heat and drought. Thanks to potassium, sugars accumulate in fruits. However, excess potassium in the soil also does not go in vain – the tips of the roots of the plant begin to die, which leads to oppression of the entire plant.

    Potassium deficiency can be determined by the appearance of the plants – the leaves lighten and dry, starting from the edge of the plate, then necrotic spots appear. Potassium chloride is an “ambulance” because it begins to supply potassium to plants already in the first 2–3 days after fertilizing.

    What is potassium chloride

    Potassium chloride, also known as potassium chloride, is a concentrated potassium fertilizer. Available in both powder and granular forms.

    The fertilizer is available on the market from different manufacturers, so the percentage of potassium chloride and its purity vary.

    Often gardeners cannot understand why potassium chloride has different colors from different manufacturers. And the color depends on what additives are contained in the fertilizer. Pure potassium chloride is white. Gray color indicates an increased proportion of chlorine. Yellowish indicates the presence of a large amount of sulfur. And pinkish-red indicates the presence of heavy metals and iron.

    Potassium chloride is a highly effective fertilizer for all types of garden and vegetable crops. However, due to the high chlorine content, it acidifies the soil and inhibits plants that do not tolerate this substance well.

    Composition of potassium chloride

    Potassium chloride (KCl) sold in retail stores contains from 52 to 60% potassium oxide. Some manufacturers produce potassium chloride with trace elements – copper, boron and zinc. The chlorine content can reach 40%, and the higher the proportion of chlorine, the grayer the color of the fertilizer (1).

    Properties of potassium chloride

    Potassium chloride replenishes potassium reserves in the soil, which plants actively consume, and helps enrich the soil with microelements.

    The optimal potassium content in the soil accelerates the growth and development of plants, improves the quality of flowering and fruit set, the taste of fruits, increases productivity, plant resistance to diseases, temperature changes and drought, and frost resistance of perennials (2).

    The use of potassium chloride in the garden

    Potassium chloride is important for the successful cultivation of plants in almost all types of soil. It is convenient because the granules quickly disintegrate in moist soil and work in the root zone for a long time.

    making Dates

    Potassium chloride is added both in spring and autumn, and also as an “ambulance” for potassium deficiency in the summer season.

    In spring, this fertilizer is applied a month before planting, mainly on light soils. And not for all plants. Cucumbers, potatoes, radishes, turnips, radishes, daikon, grapes, strawberries, and raspberries do not like potassium chloride.

    In general, it is better to apply potassium chloride in the fall, because potassium itself accumulates in the soil, and chlorine goes into the lower layers of the soil during the winter and cannot harm plants. Autumn application is most effective on heavy soils and for feeding fruit trees and berry bushes.

    To keep the soil healthy, it is recommended to alternate the use of potassium chloride with other potassium fertilizers.

    Dosage of application

    In autumn, potassium chloride is incorporated into the soil at the rate of 20 g (4 teaspoons) per 1 square meter. m. In spring – 2,5 g (1/2 teaspoon) per 1 sq. m. On potassium-rich loams, the dose is reduced by 2 times. On peaty soils, fertilizer is applied at least 2 times per season. On sandy ones – fractionally up to 3 times per season (3).

    Dosages for crops look like this:

    • when planting trees in a planting hole – up to 100 g (1/2 cup);
    • for feeding trees – 25 – 30 g (5 – 6 teaspoons) per 1 sq. m of the trunk circle in the watering grooves;
    • for root vegetables and cabbage – 20 – 40 g (4 – 8 teaspoons) per 1 sq. m;
    • for other vegetables and flowers – 10 – 20 g (2 – 4 teaspoons) per 1 sq. m,
    • for planting seedlings – 5 g (1 teaspoon) per plant.
    • for liquid fertilizing at the roots of perennials, trees and shrubs – 10 g (2 teaspoons) per 10 liters of warm water.

    Application methods

    In autumn and early spring, dry fertilizer is incorporated into moist soil.

    On peaty soils, fertilizer is applied 2 times per season. On sandy ones – fractionally up to 3 times per season.

    Fertilizer solutions are used during planting, spring and summer root feeding.

    To neutralize chlorine and more effectively use fertilizer for summer fertilizing, it is recommended to make the solution in this way: pour 20 g (4 teaspoons) of potassium chloride into 10 liters of water, add 100 g (1 glass) of wood ash, stir and leave to infuse in an open container for 1 hours. This feeding can be done even for cucumbers and tomatoes at the rate of XNUMX liter per bush.

    Popular questions and answers

    We asked about potassium chloride agronomist Oleg Ispolatov – he answered the most popular questions from summer residents.

    How much does it cost and where to buy potassium chloride?

    Potassium chloride is sold in kilogram packages at prices ranging from 90 to 300 rubles. In addition to pure fertilizer, fertilizers enriched with potassium humate or microelements are available for sale.

    You can buy fertilizer at garden centers, gardening stores and online stores.

    Is it possible to apply potassium chloride in the fall?

    Not only is it possible, but it is most effective. In addition to the fact that fertilizer applied in the fall replenishes the soil with potassium, the harm of chlorine is significantly neutralized over the winter. In addition, potassium chloride will help get rid of wireworms.

    Is it possible to do foliar feeding with potassium chloride?

    Not recommended. However, in emergency situations, a solution of pure concentrated potassium chloride, available in the form of a snow-white powder, can be used for spraying.

    How to store potassium chloride?

    Potassium chloride must be stored in a hermetically sealed container at a temperature of 18 – 20 ° C in a dry, dark room – the sun’s rays should not penetrate there.

    Is it possible to mix potassium chloride with other fertilizers?

    It is believed that potassium chloride can be combined with ammophos, urea, saltpeter, superphosphate, manure and bird droppings. Do not combine with lime and dolomite flour.

    Sources of

    1. State catalog of pesticides and agrochemicals approved for use on the territory of the Russian Federation as of July 6, 2021 // Ministry of Agriculture of the Russian Federation
    2. Mineev V.G. Agrochemistry (textbook, 2nd edition, revised and expanded) // M.: Moscow State University Publishing House, KolosS Publishing House, 2004.
    3. Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry (edited by B.A. Yagodin) // M.: Kolos, 2002.

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