Stewart, I have a correction on the Peters Foliar Feed...it is 27-15-12. I had the 12 and 15 transposed. Almost 80 % of the nitrogen is from Urea. Phosphorous is derived from Ammonium Phosphate and Potash from Potassium Nitrate. Plus a triple dose of micronutrients. Their directions state that a surfactant is helpful and to apply in the mornings and to avoid hot weather when doing it. Wayne