Hydrotech’s Six Pack Potassium Nitrate is a soluble source of two major essential plant nutrients. It is especially desirable in conditions where a highly soluble, chloride-free nutrient source is needed. Applications of Potassium Nitrogen to the soil are made before the growing season or as a supplement during the growing season. A diluted solution is sometimes sprayed on plant foliage to stimulate physiological processes or to overcome nutrient deficiencies. Foliar application of Potassium Nitrate during fruit development can be advantageous for some crops, since this growth stage often coincides with high Potassium demands during the time of declining root activity and nutrient uptake. It is also commonly used for greenhouse plant production and hydroponic culture.