Each year producers ask the question: When is the best time to apply nitrogen to wheat? Also, is it ok to apply nitrogen on frozen ground? For any nitrogen application the question to ask is when does the crop need nitrogen. Wheat does not require large amounts of nitrogen until stem elongation (Feekes Growth Stage 6), which is the middle or the end of April depending on the location in state. Ohio research has shown no yield benefit from applications made prior to this time period. Soil organic matter or nitrogen applied at planting generally provides sufficient nitrogen for early growth until stem elongation.