What Is Potash and What Is It Used For?

what is potash

If you have ever researched the ingredients in fertilizers then you probably have come across the term potash. The most common fertilizers containing potash are muriate of potash (potassium chloride) and sulfate of potash (potassium sulfate). It can also be found as a single ingredient fertilizer or in complete fertilizer mixes along with nitrogen and phosphorus.

So what exactly is Potash? Essentially Potash is salt, in water-soluble form, that contains potassium. It is a term used in the fertilizer industry to refer to potassium chloride or potassium sulfate, nitrate, and oxide.  Potash is the most common source of potassium used in the agriculture industry. Potassium is the K in N-P-K ratios in fertilizer.

Potassium In Agriculture

Potassium is one of the three main macronutrients that are essential for plant and animal life. Along with potassium, the agriculture industry relies on fixed nitrogen and water-soluble phosphorous to enrich and nourish the soil. These three nutrients (nitrogen. phosphorous, and potash) are necessary for healthy plants and crops and there are no substitutes for these three key nutrients.

The benefits of adding potassium as a fertilizer include:

  • Improves root health and development
  • Plays a critical role in sustaining turgor pressure in plants.
  • Increases resistance to drought by improving water storage capacities
  • Increases resistance to frost
  • Helps prevent diseases as well as damage from parasites
  • Creates added capacity for vitamins and proteins which makes a healthier and more nutrient-dense plant.

Plants show signs of a lack of potassium through a flaccid structure, leaves with yellow edges, slow growth, smaller than average leaf size, and necrosis in leaves.

Potash in Lawns

Potash in Lawns

Fertilizers that are known as “winterizers” often have a high level of potash in their mix. This is due to the fact that potassium is known to improve cold hardiness in plants including lawns. Potash can also improve the grass’s capacity to resist drought, stress, and disease.

While fall is a great time to apply potash as a fertilizer in order to repair summer damage and depletion, potash can be used year-round as the benefits of adding potassium to a lawn depleted of this nutrient can be seen in all seasons.

Potash is a health booster for lawns, and lawns that are low in potassium can result in slow growth, yellowing leaves, and poor root development. The lawn low in potassium will also be more sensitive to temperature changes as well as prone to disease.

It can be hard to know if your lawn has low levels of potassium. The only real way of finding out nutrient levels is through a soil test. These tests, either performed with a pH meter or by professionals, will give you recommendations for what types of fertilizers your soil needs and in what quantities to produce the healthiest lawns.

Potassium can be found in high levels in many types of soil naturally. However, the potassium in the soil is often in forms that plants are unable to absorb. Clay soils usually have higher levels than sandy soils, however, as the nutrient is easier to leach out of the sandy soil. Soil testing can best explain if Potassium (in K+ form) is present in adequate levels in the soil, or if additional potassium and other nutrients are needed.

Best Fertilizers With Potash

fertilizers with potash

When it comes to lawn fertilizers with Potash, you will likely find Potassium Sulfate, also known as SOP, or Muriate of Potash (Potassium Chloride), which is also known as MOP. You are likely to find that most commercial fertilizers are using MOP. Some homeowners and businesses (such as golf courses) prefer to use SOP and find that it is less harsh on lawns. I have listed a couple of recommended options below.

Click through on the text or images to find further product information on these fertilizers.

Where To Buy Potash?

Most hardware stores will carry fertilizer with potash or by-itself in liquid or granule form. I have found a few good potash products on sale at DoMyOwn and Amazon. Feel free to check these out.

TurfGrass Pro 0-0-29

turfgrass pro review

TurfGrass Pro is a high potassium liquid potash packed fertilizer. Coming in with 0-0-29 on the NPK scale. This is a great product for foliar applications and offers a low-risk for phytotoxicity. Get It here.

10 Pounds - Potassium Sulfate - Sulfate of Potash
110 Reviews
10 Pounds - Potassium Sulfate - Sulfate of Potash
  • A good source of potassium and sulfur
  • Shipped in 2 - 5 lb resealable foil bags that are sealed for safety and freshness. It includes a tear-off tab for easy opening.

Muriate of Potash

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History of Potash

the history of potash

The word potash comes from “pot ash” which refers to the way it was originally made in the 1700s.  It was first made from forest ash. Wood ash was mixed with water and then boiled in a large pot, or kettle until the moisture completely evaporated. What was left became known as black salts. The potash created in this method was a highly demanded world commodity as it was used for making things like soap, glass, fertilizer, fabric dye, and was used in the processing of wool.  In current times potash is used mainly as fertilizer for crops and in biofuels.

References and Further Reading on Potash

PennState Extension. (2016). Turfgrass fertilization: A beginner’s guide. https://extension.psu.edu/turfgrass-fertilization-a-basic-guide-for-professional-turfgrass-managers

Investopedia. (2020). 5 things to know about Potash. https://www.investopedia.com/financial-edge/1110/5-things-to-know-about-potash.aspx#:~:text=Potash%20is%20America’s%20first%20industrial,farming%20to%20fertilize%20food%20supply.

USGS. Potash Statistics and Information. https://www.usgs.gov/centers/nmic/potash-statistics-and-information

USGS. (2020). Potash. https://pubs.usgs.gov/periodicals/mcs2020/mcs2020-potash.pdf