Lawn treatment and feeding

Treatment programmes are built around four or five visits. Early spring puts down a high nitrogen feed once soil temperature holds above 6 degrees, which greens the sward and gets grass competing. Late spring is when selective herbicide goes on, hitting broadleaf weeds in active growth so the grass can close the gap behind them. Summer switches to a slower feed with less nitrogen, so growth does not outrun the available water. Autumn brings a potassium and phosphate blend that hardens the plant for winter, usually alongside iron sulphate for moss.

Certification is not optional. Anyone applying a pesticide authorised for professional use must hold PA1, the foundation unit on legislation and safe handling, plus the unit matching their equipment, which for a knapsack or hand held lance is PA6. Grandfather rights, which let operators born before 31 December 1964 spray without qualification, ended on 26 November 2015. Since then it has also been an offence to sell professional product to anyone who has not checked the end user holds the certificates.

Feeding will not fix compaction, and no quantity of iron keeps moss out of ground that lies wet. Moss is a symptom of shade, poor drainage, a mower set too low, or soil squeezed airless. Sulphate of iron in autumn blackens it within ten days, then it returns by March unless the ground has been opened up. That is why serious programmes pair treatment with scarifying and aeration in September rather than selling feed alone.