What Are the Functions of Soluble Potash in Lawn Fertilizer?

Potassium Function

• Along with nitrogen and phosphorus, potassium is a primary macronutrient required by lawn grasses, usually in larger amounts than are available in soil naturally. Potassium is key for plant growth; it activates enzymes and aids root development and nutrient processing. It also functions in the opening and closing of stomates, which regulate water intake.

Potassium Deficiencies

• Potassium is necessary for a plant's ability to tolerate environmental stresses. Potassium deficiencies affect a plant's ability to withstand drought, high temperatures, wear and tear and a variety of turfgrass diseases. Deficiencies appear as yellowing of older and lower leaf blades and eventually dieback of the leaf tip and scorching on the margins.

Soluble Potash

• White potash -- also called soluble potash -- is used in liquid starter fertilizers. White potash is highly soluble, making it readily available to plant roots. The percentage of potassium -- or soluble potash -- found in lawn fertilizers is the third number listed on the package. A 20-10-10 fertilizer, therefore, has 20 percent nitrogen, 10 percent phosphorus and 10 percent potassium.