Robust� Lawn Booster is a professional grade controlled release fertiliser designed specically for lawns. Robust� Lawn Booster provides steady strong growth for up to 4 months from application. For best results, apply in spring, summer & autumn. - Creates extra thick green lawn, helping to block out weeds. - Ideal as lawn starter fertiliser. - Provides superior, professional results - out performing traditional fertilisers. - Every granule contains the same nutrients, giving more even and robust growth. NPK: 22 : 1.3 : 5.8 COVERAGE - 2.5kg - 165m2 Established Lawns (330m2 Lawns less than 8 weeks old).