Using of Iron Sulphate in Lawn Care: Tips and Tricks

Iron sulphate, often known as ferrous sulphate, is a commonly used supplement in lawn care. It offers several benefits, from greening up the grass to treating moss. However, using it effectively and safely requires some knowledge.

Using of iron sulphate in lawn care

For many years sulphate of iron has been widely used in the lawn and turf care industry. It’s uses are varied and there are many benefits of applying this product to grass, especially now that many previously used chemicals are no longer available for use on lawns.

This versatile product can be used to control moss, discourage earthworms from casting and in certain cases control weeds and disease.

Many fertilisers used in the turf care industry contain sulphate of iron in their formulation because of the reasons previously mentioned. We will take a closer look at each of the benefits that this product has on lawns and turf.

Disease prevention & control on lawns

Diseases such as fusarium patch and take-all patch require the turf surface to be alkaline (high pH) for the fungus to be active. Applying iron to the lawn will help acidify (lower the pH) of the turf surface, therefore minimising the damage caused by the disease.

The product can be mixed with water and applied at a rate of 10g/m2 to the lawn when the disease is most active.

In the turf industry fungicides are still widely used for the control of turf diseases as they are more effective than this product. However the disadvantages of fungicides is that they also kill the beneficial bacteria (which helps to suppress the disease) as well as the pathogenic bacteria which causes the disease.

At some point in the near future fungicides may end up being banned because of their affect on the environment. If this ban goes ahead this will mean this product will play a major role in disease control in the turf industry.

Control & kill moss on lawns

Moss treatment with iron sulphate

This is the most common use for sulphate of iron in the lawn and turf industry. It is used in lawn sand along with sulphate of ammonia (nitrogen) and sand (used as a carrier) to kill moss in the spring time.

Lawn sand will kill moss very quickly, usually between 10 – 14 days, however the period of control can be short. It can also be used on it’s own at a rate of 10g/m2 to control moss in lawns.

Regular applications at the above rate about every 4 – 6 weeks during the winter months will help stop any moss invading your lawn.

It also has the added benefit of burning off certain weeds if used regularly and preventing algae problems.

Wormcast & worm control on lawns

Unfortunately there are no chemicals that are approved for worm control on domestic lawns, they are only available for turf professionals who are employed in the turf industry.

However as previously mentioned these product may soon be banned, so sulphate of iron will also play a major role in worm control in the turf industry.

Because of its acidifying effect on the turf surface, it can be quite effective in discouraging worms and reducing the number of worm casts. This is because worms do not like the acidifying effect on the surface caused by this product.

Applying sulphate of iron every 4 – 6 weeks at a rate of 8g/m2 should help reduce worm activity resulting in fewer worm casts.

Iron Sulphate in Lawn Care: Tips and Tricks

Here are some tips on using iron sulphate for your lawn:

  1. Purpose of Use:
    • Lawn Greening: Iron sulphate can give your lawn a lush green appearance as it provides iron, essential for chlorophyll production.
    • Moss Control: It’s a popular moss killer. When applied, it turns the moss black, indicating that it’s working.
  2. Application Rate:
    • Ensure you read the manufacturer’s instructions for the recommended dosage. Over-application can lead to scorched grass or iron stains on pathways.
    • Typically, for moss control, you might use around 3-5 grams per square meter, while for lawn greening, 1-2 grams per square meter is standard.
  3. Dissolving in Water:
    • Dissolve the iron sulphate in warm water to ensure it mixes thoroughly before application.
    • Once dissolved, you can add more water to get the desired concentration.
  4. Spray Application:
    • Using a garden sprayer ensures even distribution. Ensure you clean your sprayer after using it for iron sulphate to avoid corrosion.
  5. Safety Precautions:
    • Wear gloves while handling iron sulphate.
    • Keep pets and children off the treated area until it’s dry.
    • Be cautious not to spill the product on stone patios, pathways, or driveways, as it can leave rust-like stains.
  6. Weather Considerations:
    • It’s best to apply iron sulphate during calm, dry days. Rain soon after application can wash away the product, reducing its effectiveness.
  7. Aerate Compacted Soil:
    • If your lawn has compacted soil, consider aerating before application. This ensures better penetration of the product.
  8. Watering:
    • While rain soon after application isn’t ideal, watering the lawn a day after applying iron sulphate can help in better absorption.
  9. Mowing:
    • Avoid mowing the lawn for a few days before and after the application to give the treatment time to work.
  10. Check Soil pH:
  • If you’re using iron sulphate primarily for greening, ensure that your lawn’s soil isn’t overly alkaline. Iron is less available to plants in high pH (alkaline) soils. You might need to amend your soil’s pH if this is the case.
  1. Be Patient:
  • After application, it might take a few days to see noticeable results. The lawn will gradually green up, and moss will blacken and die.

In summary, while iron sulphate is beneficial for lawns, it’s crucial to use it judiciously, following safety precautions and recommended application rates. Proper use ensures a vibrant, moss-free lawn that’s the envy of the neighbourhood.

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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