Potassium is one of the macronutrients turf grasses require for healthy growth and development. Its freely available in soils but applying inorganic fertilizers can also induce it into the soil. Healthy lawns rich in potassium and other nutrients are greener, lusher, and have a uniform appearance. Potash has various benefits when applied to lawns. Is it necessary to apply potash fertilizer to grass?
Potash improves grass water retention, encourage greener texture and uniform lawn. Potash increases lawn cold hardiness that helps improve the grass’s resistance to drought, stress, and disease. When applied on the lawn, other plants also benefit in improving yields, their nutritional value, and influence their taste.
Should you apply potash to the lawn?
Potash is a healthy booster to that help to protect grass roots from frost as well as strengthen the cell walls due to better retaintion of nutrients. However, take the soil test analysis for potassium deficiency before applying potash to the lawn.
Often, potassium is available in the soil for turf to absorb and utilize. Perform a soil analysis in the lawn area or take a sample to an agricultural lab for examination. The report will show the soil pH and the quantities of available nutrients in the soil. If a potassium deficiency is present, an Agriculturalist will direct you accordingly on what type of potash fertilizer to apply to the lawn.
What does potash do to grass?
Turfs lacking potassium always have a stunted growth rate, yellowing leaves, and are more susceptible to environmental stress such as drought, cold, and higher temperatures. Potassium in turf helps to transport sugars and starch, activating enzymes and regulating plant pressure. Adding potassium-rich fertilizers (like 24-0-6 Flagship Granular) will revive such turf. If you add potash to your lawn, the grass will benefit in the following ways:
1. Grass becomes more resistant to diseases
Applying potassium-rich fertilizer to the lawn will help the grass be more resistant to diseases. This is because potassium helps in the creation of thick, more muscular turf cell walls. Muscular cell walls prevent diseases from entering the cell; therefore, the turf will be more resistant to attacks by diseases.
2. Grass survives during environmental stress
Turfs with potassium deficiency always suffer from environmental stresses such as higher temperatures, drought, and colds. This is because their cell walls are flaccid, thereby vulnerable to ecological changes. However, if a plant is rich in potassium, it will be more immune to such changes. In drought, a potassium-rich turf will have a high turgor pressure in its cells, making them rigid. They will therefore form a resistance against water loss. The turf will continue to photosynthesize using the reserved water to maintain its usual shape.
The turf withstands the cold in Winter because the potassium and sugars present in their cells saps lower the grass’s freezing point.
3. Roots become stronger and deeper
Applying a potassium-rich fertilizer helps turf grow stronger, extending its roots deeper into the soil. Turfgrass stem also become thicker. Potassium helps to build thicker turf cell walls, resulting in stronger roots and stalks. Strong roots help turf remain rooted without being washed away during rains. Deep roots can absorb essential nutrients turf requires for its growth and development. Meanwhile, a plant with potassium deficiency has shallow, weak roots which don’t actively absorb vital plant nutrients from the soil for its growth and development.
4. Healthier grass
Potassium helps in plant processes such as cellular metabolisms and managing internal water. It also activates enzymes catalyzing the physiological processes. These physiological processes ensure the healthy growth and development of turf. Potassium helps to transport sugars and starch to different parts of turf. Starch provides essential energy for internal turf processes ensuring healthy growth and development.
5. It helps grass absorb other nutrients from the soil
Potassium helps in the uptake of nutrients such as Nitrogen from the soil. When nitrogen is absorbed, it forms a chlorophyll component, which gives grass its green color. Nitrogen in turf also helps form enzymes, amino acids, and proteins, ensuring healthy turf growth and development.
6. It helps to strengthen the xylem vessels of grass
Potassium helps in strengthening the turf’s xylem vessels. Xylem vessels are the transport system of plants for water and mineral salts roots absorb from the soil. Potassium strengthens the xylem vessel cells, enabling the system to take water and minerals to the necessary parts. Turfgrass uses the water transported to perform activities such as photosynthesis ensuring food is available to the grass. Plants with less water have yellow, curled leaves.
What fertilizers are high in potash?
Both inorganic fertilizers and organic products are excellent sources of potash. Examples of organic sources of potash are animal feeds, seaweeds, animal beddings, and wood ash. Inorganic fertilizers are manufactured in industries. While some inorganic fertilizers have no potash, some have small percentages, and others have high amounts of potash. Below are the best three fertilizers with high potassium levels.
1. Muriate of potash
Also called potassium chloride, muriate of potash has the highest percentage of nitrogen in all fertilizers. It has a configuration of 0-0-60. The composition shows the percentage of each macronutrient in the fertilizer. This arrangement demonstrates the fertilizer has 0% Nitrogen, 0% Phosphorous, and a whopping 60% Potassium concentration.
Muriate of potash exists in granular form, though it can be dissolved in water and sprayed on foliage. It’s the most concentrated fertilizer but still the most cost-effective fertilizer.
Potassium chloride has equal size granules between 2-4mm, ensuring its accurate spread on the lawn. Apply muriate of potash in all types of soil and chloride tolerant crops.
2. Sulfate of potash
Otherwise called potassium sulfate, this fertilizer is rich in potassium and sulfur nutrients turf requires for healthy growth and development.
The sulfate of potash has a configuration of 0-0-50. This configuration means it has no Nitrogen and Phosphorus nutrients but has a 50% potassium concentration. It exists in granular form and is water-soluble. It’s expensive and best applied on chloride-sensitive crops such as tobacco and tomatoes.
3. Potassium Nitrate
Potassium nitrate fertilizer is a source of both potassium and nitrogen macronutrients. It has a configuration of 13-0-44. This arrangement indicates it has 13% Nitrogen, no Phosphorus, and 44% Potassium concentration.
Potassium nitrate exists in granular form. It is moderately soluble in water and applied best before or during the growing season. Potassium nitrate is effective in areas where immediate potassium uptake is needed because it releases soluble fertilizer quickly. Apply potassium nitrate in chloride-free soils.
When to apply potash to my lawn
Apply Winterizer fertilizers to the lawn in Autumn to prepare the turf for the cold Winter season. Remember, potash-rich fertilizers help the turf form a resistance against the cold by increasing turgor pressure in the cells.
You can also apply potash before the growth window and during the growth window. Here, the plant will be actively growing, and potassium would help it grow stronger roots and stems, uptake more other nutrients from the soil and grow healthy.
Also, add potash fertilizer to the lawn in late spring or summer. Potassium will help the plant withstand hot summer temperatures by increasing turgor pressure, which allows the plant cells to remain rigid. Rigid plants don’t wilt and will continue to photosynthesize to produce more turf food.
Generally, potash fertilizers are conducive to applying in all seasons, depending on your soil nutrient composition and turf requirements.
Can Potash burn grass?
Potash cannot burn grass because of its low salt index per unit of potassium nutrient in fertilizers. But, When do you Fertilize New Sod?
The salt index of potash is fertilizers per unit is between 0-2. This value is too low to burn grass or new sods compared to other nutrient salt values such as nitrogen, which has a high value of 7.
However, excessive application of potash fertilizers can be harmful and unhealthy to lawns. This is because too much potassium in the soil interferes with the uptake of other nutrients such as nitrogen. Turf lacking nitrogen have yellowing leaves, stunted growth and are susceptible to pests and diseases.
- Joesph Heckman, Extension Specialist in Soil Fertility and James A Murphy, Extension Specialist in Turf Management, New Jersey Agricultural Experiment Station: Fertilizing the Home Lawn.
- NC State Extension Publications: Caring for Your Lawn and the Environment.