Ammonium Sulphate or Sulphate of Ammonium can create a green lawn faster than most other products but it comes with a warning. Before using Ammonium Sulphate you should carefully consider the drawbacks. Essentially Ammonium Sulphate is straight Nitrogen, a main element in lawns and the N in the NPK ratio often displayed on fertilising products. Being the primary nutrient responsible for green leaf growth, Nitrogen applied on its own will quickly increase green leaf growth but the drawback is that it will not support any other normal developmental processes that your lawn requires. Ammonium Sulphate applications will supercharge the green leaf growth, but at what cost to the long term health of the lawn?
Rapid leaf growth leads to the potential that your lawn will become scalped after the next mowing or even the next few mowings. Scalping, in turn, can lead to overall poor health which encourages pest infestation, weed infestation and disease. Your lawn can also struggle to self-repair and can even die if the soil dries out too quickly. Additionally, if the crowns of the lawn raise too high during the leaf growth process and are then removed during lawn mowing, that section of lawn is likely to die.
Even if applied in a controlled manner, Ammonium Sulphate is only ever supplying your lawn with one nutrient. Your lawn also needs elements of Phosphorous and Potassium and other trace elements. Without these additional elements your lawn will always struggle to reach and maintain good health. Ammonium Sulphate is mainly stored within the lawn’s green leaf so when you increase the frequency of mowing to match the rapid growth, the stored Nitrogen is removed along with the removed leaf. So, the result from applying Ammonium Sulphate is only every likely to be temporary. A much better option is to apply a balanced, high quality fertiliser regularly throughout the year; your lawn will receive all the nutrients it required to reach and maintain the best possible health. If you still decide to apply Ammonium Sulphate only apply it in small quantities and only when absolutely necessary.