What Can I Use to Add Potash to My Soil?

Potassium

• Potash is a form of potassium that is readily available to plants for use in their metabolic activities. Potassium is the second most important plant nutrient, after nitrogen. Potassium supports root growth, builds cold hardiness and protects plants from infection. It also helps aid in bloom and bud development. Potassium is found in four states within soil. Inaccessible potassium is the most prevalent. It is derived from mica and feldspar particulates found in soil. This type of potassium is not taken in by plants. Plants use exchangeable, or readily available, potassium. This form is found within the soil solution -- the hydrated portion of soil structure. When you add potash to your soil it will join this solution and become readily available for plant uptake. Other forms of potassium are limited. Organic matter provides minimal potassium to soil and plants while unexchangeable potassium is a backup supply that is not readily available but can still be processed by plant root systems.

Chemical Fertilizers

• Chemical fertilizers that contain readily available potassium are found in garden centers and nurseries. When purchasing fertilizer, you will notice that fertilizers are classified by type. Types are distinguishable by their components. A 16-16-16 fertilizer contains 16 percent nitrogen, 16 percent potassium and 16 percent phosphate. A fertilizer with a high middle number is high in potassium. Potassium-only solutions include potassium chloride, also called muriate of potash, and potassium sulfate as well as potassium magnesium sulfate. When applied in accordance with soil test recommendations, these potassium supplements will give your soil the potassium it needs to allow healthy plant growth.

Organic Fertilizers

• A garden crop with yellow leaves and scorched foliage is likely suffering from a potassium deficiency. Organic matter such as compost and manure provide little readily available potassium. Some chemical forms of the nutrient are considered safe for organic gardens and produce. Potassium magnesium sulfate and potassium sulfate are considered organic compounds and can be used to grow organic crops. Some organic gardeners also incorporate wood ash into their soil as this byproduct contains readily available potassium. Small amounts can be incorporated into surface soil around any non-acid loving plant.

Considerations

• Potash is extremely water soluble. Be aware that when potash is washed from soil it may leave behind a salt residue. Excess potash can elevate sodium levels in soil. Always conduct a soil test before incorporating amendments or fertilizers into your garden plot. These tests will recommend fertilizer dosages. Following the recommended dosage helps prevent soil structure damage and toxicity, such as excess salt.