What does lawn sand do?

Lawn sand contains ferrous sulphate (kills moss and greens grass) and sharp sand (improves drainage). It is a traditional spring lawn treatment.

When should I apply lawn sand?

Apply in April-May when grass is growing and moss is active. Apply on a dry day when rain is expected within 48 hours.

How quickly does lawn sand work?

Moss starts blackening within a few days. Rake out dead moss after 10-14 days. The greening effect on grass is visible within a week.

Can lawn sand burn grass?

Yes, if over-applied or used in hot, dry conditions. Stick to recommended rates and water in if rain does not arrive within 2 days.

Is lawn sand safe for pets?

Keep pets off treated areas for 2-3 days or until rain has washed the product into the soil. The iron sulphate in lawn sand can stain paws and is mildly irritating.

GardenCalcs

Lawn Sand Calculator — Moss Control & Greening

Calculate lawn sand quantities for moss control and greening.

Lawn Area

Price per kg (optional)

How We Calculate This

Standard lawn sand application rate is 70 g/m². Some products vary between 50-100 g/m² — check your specific product.

Formula: Total = Area × 70 g/m² ÷ 1000 = kg

Frequently Asked Questions

Related Calculators

Lawn Seed Calculator

Calculate how much grass seed you need for a new lawn or overseeding.

Turf Roll Calculator

Work out how many turf rolls you need to lay a new lawn.

Lawn Feed Calculator

Calculate the right amount of lawn fertiliser for your grass area.

Lawn Area Calculator

Measure your lawn area including irregular shapes and obstacles.

Overseeding Calculator

Calculate seed rates for patching and thickening existing lawns.

Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.