Lawn sand for moss control

What is lawn sand

Lawn sand is a popular product used in lawn and turf care. It is most commonly used during the spring time for moss control in lawns.

Lawn sand comes as a powder formulation and contains 3 ingredients. These ingredients are:

  • Sulphate of iron – This is the ingredient in lawn sand that kills the moss in the lawn. To a lesser extent it also helps burn off any broad-leaved weeds that maybe be present and it helps harden the lawn against certain diseases.
  • Sulphate of ammonia – This is a nitrogen based fertiliser that is used in lawn sand to feed the lawn and encourage growth. This helps the lawn thicken up and make a speedy recovery once that moss has been removed. Sulphate of ammonia is used because it is a quick acting product that encourages a rapid green up.
  • Sand – The sand is a carrier, simply used to bulk up the lawn sand ingredients. It will not have any benefits on the lawn.

A typical lawn sand mixture would be 1 part sulphate of iron, 3 parts sulphate of ammonia and 20 parts sand, although this may vary somewhat between various manufacturers.

N. b. Some lawn sand products may not contain sulphate of ammonia.

When to use lawn sand

As mentioned previously lawn sand is mainly used during the spring time for killing moss in the lawn. In most cases early – mid March is a good time to apply lawn sand to the lawn.

This is because the ground is starting to warm up and the grass will be starting to show signs of growth. It is best to avoid apply lawn sand too early, as if the grass isn’t growing, the lawn will take longer to recover when the moss is removed, and in some cases it may return.

Therefore wait until there are signs of grass growth before you apply this product.

However lawn sand can be used at any time during active growth, especially if moss is causing problems.

How to apply lawn sand

Lawn sand is best applied through a fertiliser spreader as this helps apply the product evenly and accurately. Ensure the spreader has been calibrated correctly to ensure it is applied at the correct rate.

The product should be applied at the manufacturers recommended application rate to avoid damage to the lawn. Lawn sand is often applied at 135g per square meter or 4oz per square yard, however it may vary between different manufactures.

It is important to know the spread width of your spreader. If you are using a drop spreader then the width is self explanatory. However if you are using a spin spreader you need to know how for the spreader throws the lawn sand. I.E. If your spread width is 6 feet, 3 feet either side, then 6 feet will be your working width.

If 6 feet is your working width then you could lay string lines down at 6 feet intervals for an even application. Alternatively some people may prefer to use markers at each end of the lawn, or some people simply use the mower breeds to gauge the spread width.

If possible mow the lawn a few days prior to applying the lawn sand. Ideally lawn sand should be applied on a still day to prevent the product being blown about. The grass should be dry when the lawn sand is applied. Avoid applying lawn sand when the soil is too dry.

Following the application, it is best to avoid walking on the lawn until the lawn sand has been washed in. If insufficeint rain falls within 2 days of applying, water it in thoroughly.

If the lawn turns black following the treatment, don’t be alarmed as this is perfectly normal. After 2 weeks the moss can be removed with a suitable hand rake or a powered lawn scarifier.

Following removal, there may be some thin or weak areas on the lawn, especially if the moss invasion was particularly bad. These areas can be repaired with a suitable grass seed and top dressing to help restore the lawn to its former glory.

Oliver Thompson
Lawn Care Expert

About Oliver: Oliver Thompson, a seasoned lawn care expert from the Cotswolds with over two decades of experience, invites all enthusiasts to join him in exploring the world of lawns, sharing knowledge, and fostering a vibrant community of lawn enthusiasts. More info

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