What does NPK mean on fertiliser?

NPK stands for Nitrogen (N), Phosphorus (P) and Potassium (K) — the three primary macronutrients. The numbers represent the percentage by weight of each element. For example, 12-12-17 contains 12% nitrogen, 12% phosphate and 17% potash. Higher N promotes leaf growth, higher P promotes root development, higher K promotes disease resistance and hardiness.

When should fertiliser be applied to turf?

Apply fertiliser when grass is actively growing and soil temperature is above 5°C. Spring fertiliser (high N) from March onwards. Autumn fertiliser (low N, high K) in September-October to harden turf for winter. Avoid applying to frozen or drought-stressed turf, or immediately before heavy rain.

What fertiliser is best for alkaline soils?

On alkaline soils (pH above 7), nutrient availability is reduced. Use fertilisers containing chelated micronutrients (EDTA or EDDHA chelated iron) to maintain availability at high pH. Acidifying fertilisers containing ammonium sulphate can gradually lower soil pH.

How do I apply granular fertiliser evenly?

Use a calibrated rotary or drop spreader set to the manufacturer's recommended rate. Make overlapping passes — rotary spreaders should overlap by 50% of spread width. Calibrate before each use by weighing output over a measured area. Apply when grass is dry to prevent granules sticking to leaf blades.

What is the difference between slow-release and fast-release fertiliser?

Fast-release fertilisers dissolve quickly and deliver nutrients immediately — ideal for quick green-up or recovery after stress. Slow-release fertilisers use coated granules that release nutrients gradually over 8-16 weeks, providing sustained growth, reducing scorch risk and minimising leaching.