13:00:45 this provides excellent green-up in low-temperature conditions. Apply in the fall for extra protection against drought and winter stress. N-P-K 13-00-45 Water Soluble Fertilizer contributing nitrogen 13 % and potassium 45 %. Potassium nitrate is a unique source of potassium by its nutritional value and its contribution to the health and yields of plants. Potassium nitrate outperforms other potassium fertilizers on crops of all types. Potassium nitrate increases yields and improves quality in vegetables, field crops, flowers and fruit and nut trees. Potassium nitrate is an ideal source of N and K for optional plant nutrition. It is available in a variety of compositions and formulations, to suit specific crop requirements and growth environments.