What is Lawn Sand and What Does it Do

What is Lawn Sand and What Does it Do?

Despite being considered a dated method for moss and weed control on garden lawns, lawn sand is still a viable treatment, offering the same benefits as modern moss and weed killer products. In fact, you may find it is the best way to remove unwanted growth from the lawn while encouraging healthier growth.

Check out the guide below for all the important info you need to know about lawn sand

Lawn sand is a lawn care product still sold at most garden centres. As the name suggests, sand is one of the primary ingredients, although there are two other important components – iron sulphate and ammonium sulphate.

Still, it does look and feel like normal sand, just with some added ingredients to help with lawn maintenance. Here’s a breakdown of each ingredient:

Iron Sulphate

Iron sulphate, often called ferrous sulphate, is the active ingredient found in moss killing lawn care products. This is what kills off moss, removing all moisture from the plant until it blackens and dies. When applied it kills moss in about 2 weeks, after which it is raked/scarified out, while it can kill various broad leaved weeds without harming the grass.

By removing moss, your lawn is much healthier as the grass does not need to compete with it for air, moisture, and nutrients. While killing moss leaves behind gaps, you easily solve this by reseeding the area.

Ammonia Sulphate

This ingredient acts as a lawn fertiliser, containing nitrogen that helps encourage healthier root and foliage development on the lawn. Because moss leaves a lot of damage to the lawn, this helps with the repairing process, ensuring lots of greener grass regrows in the space rather than weeds.


The sand is the main carrier of the product, so while it does not provide the grass with any nutritional benefit it does make distributing the moss killer and fertiliser ingredients much easier.

When to use lawn sand?

The best time to use it is at the early to mid-spring, although this does differ depending on where you live and the general weather conditions at the time.

For most people, this falls between the end of March and mid-April, although remember that the conditions can vary significantly so you may need to use it earlier or later than this.

A good way to determine when to use it is by checking your grass for signs of growth. You want to see early grass growth common at the start of the growing season, as this means the weather is warm enough for the soil to absorb the ammonia sulphate.

Technically, you can apply it before it warms and it will kill moss and weeds, but you don’t get the benefit of added fertiliser so it is well worth waiting for ideal conditions.

You can also use it during summer if needed, although the conditions are often less suitable so the results may not be as good. Plus, if you leave weeds and moss for too long the lawn may not have enough time to recover during the growing season.

Make sure you avoid the temptation to use it too early. You want it to be warm enough to get all the benefits!

It is recommended that you cut the lawn before applying, as this ensures maximum contact with the moss on the upper layer of the lawn.

How to apply lawn sand?

Applying the product is quick and easy, as you can do it entirely by hand, although results are usually better when applied using a spreader device.

In any case, make sure to get the correct rate of application for your lawn. 100 grams per square metre is the average application rate, although it does differ from manufacturer to manufacturer, so make sure to check guidelines for clarity.

You want to make sure you get the right rate of application otherwise it may cause damage to the lawn. Once you measure the right amount, split it into two piles as you want to spread from two directions to ensure maximum coverage.

Using Your Hands

Working with the first pile of product, fill both hands and start walking in one direction across the length of the lawn. This can be left to right, north to south, or vice versa.

You want to get even distribution by spreading in opposite directions, so once you finish the first batch distribute the second using the same method but go in the opposite direction. For instance, if you went left to right you would go right to left with the second batch.

Using a Spreader

Keeping the product in two piles, add the first pile into the spreader, turning the opening to around halfway. Move the lawn spreader up and down the length of the lawn, just like you would when mowing the lawn.

Once finished with the first batch, add the second and go back to your original starting position. This time, rotate the spreader 90-degrees from the first pass, repeating the process across the entire lawn.

This does mean you need to go across the lawn twice but it ensures even distribution for the best results.

Water the Lawn

If it doesn’t rain within 48 hours make sure to thoroughly water with a garden hose pipe to activate the ingredients. Make sure pets and children don’t touch the lawn for a few days after it is watered.

Last update on 2024-07-19 / Affiliate links / Images from Amazon Product Advertising API

About The Author