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Wednesday, January 20, 2016

The Truth About Sulfur for Gardens

Sulfur is needed in horticulture for two reasons; first, it is a major plant nutrient required by plants and secondly sulfur helps lower the acidity or pH of the soil. Alkaline soils, like ours and most desert soils, are made better for most plants, by reducing the alkalinity and making the soil more acidic. Sulfur, in its pure form, lowers soil pH under the right conditions.
Granular sulfur

Learn what these conditions are and promote the better use of sulfur.

How Sulfur Works

Bags of sulfur that you buy from Viragrow or a nursery is normally about 98% pure sulfur. Unless it is a special type of sulfur, it is in a granular form. For granular sulfur to work, it must come in contact with water. Once in contact with water, the outside surface of the granule dissolves releasing sulfur into the soil. The smaller the granule, the more surface area is exposed to water and the faster it dissolves and works.
Viragrow's soil sulfur fertilizer is 98% pure. 20 lb costs $20. Use one cup per cubic foot of soil to lower soil pH.
The sulfur released in water reacts with the soil chemistry to produce many different sulfur products available to plantS through its roots. Plants that take up soil water through the roots have an adequate amount of sulfur for growth and development when any kind of sulfur is present.

Sulfur Lowers Soil Alkalinity or pH

Soils in the Las Vegas Valley are rich in sulfur, usually in the form of sulfates. But the soil pH hovers around 8, not the best soil pH for plant growth. The Las Vegas Valley has companies that mine gypsum for making wallboard. Gypsum, chemically, is calcium sulfate. Sulfur in the form of sulfates and gypsum is common in the soils of our Valley. If sulfur is common in Las Vegas soils then why is the soil pH so high?

The Sulfur Problem

The FORM of sulfur dictates if soil pH will lower or not. For sulfur to reduce soil pH sulfur must be converted to sulfates. The change of pure sulfur to sulfates creates acidity and lowers soil pH. Gypsum, or calcium sulfate, contains sulfur as sulfates. The sulfur in gypsum cannot lower soil pH.

Pure granular soil sulfur will lower soil pH IF it dissolves in water and IF soil microorganisms convert it to sulfates. The speed of this change from sulfur to sulfates and release of acid depends on MOIST soils that are WARM and the size of the sulfur granule.

LOWER SOIL PH = WARM SOIL + WET SOIL + SOIL GRANULE SIZE

This granular sulfur was thrown on the soil surface two years ago to lower soil pH. It still sits there, unused. because the sulfur is not wet and the granules are too large.

Lower Soil pH the Correct Way

Recognize that lowering soil pH with sulfur occurs when temperatures are warm. Recognize that the soil must be moist. Recognize that the sulfur must be pulverized or a dust if it works.

If you have soil sulfur in granular form, crush it before you apply it to the soil. Mix the crushed sulfur with the soil and make sure the soil remains moist. Expect results when soils are warm, not when they are cold.

Use Disperul Sulfur

Viragrow has a sulfur available that dissolves easily in water because of its form. This product is called Dispersul. The soil must still be wet and warm for it to work but Dispersul dissolves easily in water. It is available now from Viragrow, 50 pounds for $25.
Viragrow's Dispersul, a water soluble sulfur that avoids the problem of granule size and slow soil reaction.
Viragrow Delivers!

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