GNP IRON TOPDRESS Fertiliser 20KG – Slow-Release Formula for Dark Green Lawns

Frequently asked questions

What do the three numbers on a fertiliser bag mean?

They are the N-P-K ratio - the percentage by weight of nitrogen (N), phosphorus (P) and potassium (K). Nitrogen drives leaf growth and colour, phosphorus supports roots and establishment, and potassium builds stress and disease tolerance. A blend like 15-4-12 is 15% N, 4% P and 12% K, which suits an established lawn; a higher-phosphorus starter blend suits new turf.

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

Fast-release (soluble) fertilisers green the lawn within days but are used up in a few weeks and can burn if over-applied in heat. Slow-release fertilisers feed steadily over 8 to 12 weeks or more, give even growth and are far more forgiving in summer. Many turf managers use slow-release as the base feed and a light liquid feed for a quick colour lift.

How much fertiliser does my lawn need?

Granular turf fertilisers are typically applied at 2.5 to 5 kg per 100 square metres, so a 500 square metre lawn needs roughly 12.5 to 25 kg - about one standard bag per application. Spread it evenly with a spreader and water in straight away. Always follow the rate on the bag, as concentrated blends are applied at lower rates than general-purpose ones.