Potassium is one of the three main nutrients found in plants, along with nitrogen and phosphorus. Some plant species need a lot of potassium for healthy and vigorous growth, which is why they should be supplied with a special potassium fertilizer. You have the choice between so-called single nutrient fertilizers or potassium-rich universal fertilizers. Read when it makes sense to use which potassium fertilizer and what you should consider when using it.
Some plants need a lot of potassium
Our recommendations
our recommendation
Patentkali 25 kg Kali Fertilizer Vegetable Garden Universal Flowers Original K S
33.90 EUR To the product| quantity / packaging | 25 kilograms |
|---|---|
| Enough for | about 250 square meters |
| potassium content | 30 percent |
| More nutrients | Sulfur 42.5 percent, magnesium 10 percent |
| price/kg | about {PRICE/25} EUR |
Patentkali is one of the most popular potassium fertilizers. In addition to a high proportion of potassium, the product also contains sulfur and magnesium. Patentkali is offered as low-dust and easy-to-spread granules, which are simply spread and then watered vigorously - the fertilizer granules gradually dissolve on contact with water and then seep into the soil. According to customer reviews, this product takes a few days to fully dissolve. Patentkali is versatile, suitable for all types of soil and plant locations. It is also approved for use in organic farming.
our recommendation
Dehner phosphate potash fertilizer with long-term effect, 10 kg, for approx. 100 sqm
13.99 EUR To the product| quantity / packaging | 10 kilograms |
|---|---|
| Enough for | about 100 square meters |
| potassium content | 15 percent |
| More nutrients | phosphate 10 percent, sulfur 12 percent, magnesium 5 percent |
| price/kg | approx. EUR {PRICE/10} |
In addition to a high proportion of potassium, this potassium fertilizer from Dehner also contains phosphate, sulfur and magnesium. The product is available in low-dust granulate form, which you simply apply to the area to be fertilized - ten kilograms are sufficient for around 100 square meters, depending on the soil composition and planting. The advantage of this potassium fertilizer lies in the integrated long-term effect, whereby part of the rock phosphate contained can be immediately absorbed and utilized by the plants. The product is particularly suitable for the fertilization of useful plants, especially heavy-consuming vegetable plants as well as fruit and berry trees.
our recommendation
Kalimagnesia Patentkali potash fertilizer granulated 5 kg
EUR 11.80 To the product| quantity / packaging | 5 kilograms |
|---|---|
| Enough for | about 100 square meters |
| potassium content | 30 percent |
| More nutrients | Sulfur 17 percent, magnesium 10 percent |
| price/kg | about {PRICE/5} EUR |
This potassium fertilizer from the manufacturer Beckmann also contains high levels of sulfur and magnesium and is therefore a valuable mineral fertilizer for many useful and ornamental plants. The low-dust granules are low in chloride and are particularly suitable for chloride-sensitive plant species, which include many fruit and vegetable plants also include sunflowers, grapevines and hops. The potassium fertilizer strengthens the plants and makes them less sensitive to various pathogens. In addition, the application increases the formation of flowers and fruits and thus increases the yield. The product is also suitable for treating an existing potassium deficiency.
Purchase Criteria
Type of potassium fertilizer
There are different types of potassium fertilizers. The potassium content varies depending on the species, and various other nutrients - such as magnesium and sulfur - are also added. Other products, on the other hand, are not pure potassium fertilizers, but multi-component fertilizers with an emphasis on potassium. Here we briefly present the most important species for use in kitchen and ornamental gardens.
Patent Kali: Patentpotash - also known as potash magnesia - contains magnesium and sulfur in addition to potassium. This potassium fertilizer is easily soluble in water, so the nutrients are quickly available to the plants. As a rule, patent potash is obtained from the naturally occurring mineral kieserite, which is why it is a natural product. Patentkali is low in chloride or chloride-free and is therefore also suitable for sensitive garden plants such as rhododendrons.
Thomaskali: Thomas or phosphorus potash consists of the main components potassium and phosphorus, and magnesium is also included. This potassium fertilizer has a granular structure that is easy to apply in the garden. Thomas potash is a by-product of the production of steel or iron. Sometimes the fertilizer is also referred to as Thomas flour.
potassium sulfate: Potassium sulphate has a very high proportion of potassium and a similarly high proportion of sulphur. It is a fine to coarse-grained, white salt, which is very well suited for liquid fertilization. Since potassium sulphate, chemically speaking the potassium salt of sulfuric acid, is also low in chloride, you can use it to fertilize sensitive plants such as raspberries or blackberries.
Potassium fall fertilizer: In addition to the potassium fertilizers presented, there is a range of autumn fertilizers, which are mostly multi-component fertilizers with a greater or lesser concentration of potassium. The strong emphasis on potassium in fertilizers applied in autumn can be explained by the antifreeze effect of potassium, which protects the plants from damage in winter.
Potassium Lawn Fertilizer: Potassium-rich lawn fertilizers are also special autumn fertilizers that are tailored to the needs of the lawn grass and are intended to protect the lawn from frost damage in winter.
fertilizer form
Solid fertilizer/ granules: Potassium fertilizers are mostly available in granular form, which is particularly easy to apply. The fertilizer granules are simply spread over the intended area - you should definitely follow the manufacturer's instructions for dosing, because over-fertilization can have serious consequences - and slowly dissolves after repeated vigorous watering.
liquid fertilizer: The use of a liquid potassium fertilizer makes sense if the nutrient should or must be available to the plants as quickly as possible. Liquid fertilizer is given together with the irrigation water and immediately seeps into the roots.
grit
Fertilizer granules are available in different grain sizes. So you can choose potassium fertilizer from fine to coarse granulation, with other factors also playing a role in the choice in addition to the intended area of application. The finer the granulation, the faster it dissolves and seeps into the ground - but the more likely it is to dust and fly away with the wind.
quantity / packaging
Whether you choose a 50, 25 or 5 kilogram bag of potassium fertilizer depends on how large the area to be fertilized is. In principle, you can supply around 100 square meters of garden with ten kilograms of fertilizer, although this is of course an estimate. This can be higher or lower depending on which plants you want to fertilize - some species need more potassium than others. For lawns, you should plan around 50 to 70 grams per square meter.
youtubefrequently asked Questions
What is potassium?
Potassium is a natural chemical that occurs in every soil - but mostly in a bound form, which is why it is only available to plants to a limited extent. Potassium is also naturally present in plants, but is used up with the age and growth of the plant and cannot be regenerated by it.
What do you need a special potassium fertilizer for?
When the natural potassium stores in the plants are emptied, older leaves and shoots eventually die. An additional supply of the nutrient ensures that the plants remain healthy and strong, grow better and can also defend themselves against diseases and pests.
In which garden areas is it useful to use potassium fertilizer?
Potassium fertilizer is particularly often used for autumn fertilization of lawns. But it also makes sense to use it in kitchen and ornamental gardens, for example to winterize shrubs and other woody plants. After all, woody plants in particular need a lot of potassium, as do some useful plants. The latter should be protected against diseases such as blossom end rot with the addition of potassium, and potassium fertilization also increases the yield.
What types of potassium fertilizer are there?
Pure potassium one-component fertilizers are hardly available, mostly potassium fertilizers are mixtures of two or three nutrient elements or a multi-component fertilizer with an emphasis on potassium. Additional ingredients can also be added to the fertilizer, for example weed killers and moss killers. The latter are intended for the fertilization of lawns.
How do you recognize a potassium deficiency?
A potassium deficiency is particularly evident in older plants and on sandy or calcareous soils. Affected plants are very susceptible to diseases and pests, grow poorly, and old shoots suddenly die. In fruit trees, ripe fruits do not have the desired aroma, and blossom end rot occurs more frequently. Leaves yellow and typically exhibit a brown, necrotic leaf margin.
Can too much potassium also be harmful?
Be sure to follow the manufacturer's fertilizer recommendations, as over-fertilization with potassium can acidify the soil. As a result, the plants no longer absorb other important nutrients in sufficient quantities, and an excess of potassium leads to damage to the roots and can ultimately cause the death of the plant.