Work out grass seed quantity instantly with clear inputs, formula shown and shareable results.
Seeding rate is 25-35 g per square metre for a new lawn, around 70% of that for overseeding into existing grass, and considerably more for patch repair where competition is absent. Sowing too heavily causes damping off as seedlings compete.
Seed quantity
seed (kg) = area x rate (g/m2) / 1000, with the rate adjusted for the purpose
No. Overcrowded seedlings compete for light and water, producing weak grass prone to fungal disease. Correct rate plus good preparation gives a denser lawn.
Early autumn is ideal — warm soil, reliable moisture and little weed competition. Spring works but needs more watering.