Everything you need to know, including dosages
Lawn sand is an effective lawn and turf treatment
Find out why here
Lawn sand was once a very popular treatment that both professionals and DIY gardeners used, but more and more non-professionals are now using alternative chemical treatments, including liquid products.
You’ll find plenty of lawncare expects still using lawn sand on sports fields and ornamental lawns, and for good reason – it has many benefits, and the surface remains child and pet safe.
On this page, I’ll explain what lawn sand is, when and how to use it, the best dosages, the results you can expect, and I’ll suggest some alternatives too.
What is Lawn Sand?
Lawn sand is a treatment typically used on well-tended domestic lawns and sports fields, it consists of two to three ingredients:
- Iron sulphate.
- Ammonium sulphate (optional).
While the exact ratios vary from manufacturer to manufacturer, most mixes contain around 2-4% iron.
Lawn sand is used for several purposes, including:
A general feed – lawns look greener after an application of lawn sand due to the iron which is a fertiliser.
Moss control – iron is one of the best ways to kill, control and prevent moss and is also fast-acting, so you can expect results in days, not weeks.
Changing the soil pH – lawn sand will change the soil’s pH, which deters worms (so fewer worm castings) and alters the colour of the grass, which should be noticeably greener after an application.
Weed prevention – regular lawn sand applications should help create an environment where grass thrives, but weeds struggle to take hold. It also kills off some types of weeds that are already present.
As an alternative to pesticides – although lawn sand contains iron and thus nitrogen, it’s much safer than many alternatives which often contain pesticides or herbicides to kill moss, weeds and pests.
Drainage – sand helps with drainage which prevents waterlogging and disease.
What You Shouldn’t Use Lawn Sand For
As lawn sand contains iron sulphate and possibly ammonium sulphate, it shouldn’t be confused with regular sand, horticultural sand or kiln-dried sand.
Lawn sand is a treatment product and shouldn’t be used on its own for lawn levelling or top-dressing (although it can be used as an additive to other mixes).
The incorrect or excessive use of this sand can cause all sorts of problems, so it should only be used as a treatment product at the suggested doses.
Recommended Application Rates and Timings
The dose will depend on the composition of the lawn sand, and as every product is different, you’ll need to refer to the packaging or manufacturer’s website for application rates.
As a general rule of thumb, lawn sand containing 2% iron is usually applied at a rate of 125-150 grams per square metre, while sand with 4% iron should be applied at a rate of 60-75 grams per square metre of lawn.
The best time to apply lawn sand is during the growing season, which starts in spring, as this ensures the grass has time to recover.
The application of this sand can be repeated every 4-6 weeks depending on well the lawn responds to the treatment.
How to Apply Lawn Sand
As lawn sand contains iron, there is the potential for it to scorch the grass; precise application rates are therefore crucial.
Lawn sand can be applied to large areas via towed mechanical spreader.
For medium-sized lawns, a pushed spreader will suffice.
For smaller gardens, a handheld spreader would be the best option.
We do not recommend applying lawn sand by hand as it’s far too inaccurate.
If you’ve never used lawn sand before, follow these steps:
- First, if the lawn sand is wet, allow it to dry out as wet sand will clog the spreader.
- Then, cut the grass and collect the clippings.
- Apply the lawn sand at the recommended rates.
- The lawn should then be watered, no later than 48 hours after application.
- Water and brush off any sand from hard surfaces to prevent staining.
What to Expect
The lawn sand should start killing off the moss within a week, and if the infestation is severe, the moss will turn a black colour so you may wish to re-seed at the same time to fill in any gaps.
The grass should start to green-up in 2-4 weeks.
Drainage, weed prevention and other improvements will happen over time and after repeat applications of the lawn sand which isn’t a “one and done” treatment.
What Not to Expect
While lawn sand can kill some weeds, it isn’t a targeted weed killer, so if you have a severe infestation of weeds, it’s unlikely you’ll see results and certainly not after just one application.
Lawn sand is effective at controlling moss, but one application is unlikely to kill off a severe infestation which should first be treated with a dedicated moss killer. Lawn sand can then be used to prevent the moss from returning.
Lawn sand will work best when applied every 4-6 weeks as part of a maintenance program; you’re unlikely to see long-lasting improvements to drainage, colour or grass vigour after just one or two applications.
There are three problems with lawn sand worth noting:
- First, excess iron can scorch the grass, hence why a spreader should be used. Also, many other garden products contain iron or nitrogen, so one should be careful when combining products.
- The iron in this product may permanently stain concrete, patio slabs, carpets and clothes.
- It won’t cure a severe moss infestation, and some gardens will require a more dedicated moss treatment regimen.
Lawn Sand Safety
When used as directed, lawn sand is very safe for pets, wildlife and children.
After applying and watering the product in, children and pets should be kept off the grass until the area has dried.
Hands, tools and shoes should be rinsed to remove any iron that could cause stains.
If too much lawn sand is used, the grass may scorch but will likely recover.
Here are the pros and cons of lawn sand:
- Cheap, especially when purchased in bulk; a 25kg bag will cover up to 450 sq metres of lawn.
- An excellent all-round maintenance product.
- Improves soil pH and deters worms and other burrowing insects from the top layer.
- Controls moss, prevents it from spreading and can kill mild infestations.
- Safer than many chemical-laded alternative products.
- Greens up the lawn and de-thatches the top layer which improves drainage.
- It isn’t a dedicated moss killer and won’t cure severe infestations.
- Moss that’s killed will turn black and look unsightly; there are better ways to get rid of moss that won’t ruin the appearance of the lawn.
- It will control many weeds but isn’t effective at killing off severe weed infestations.
- It’s easy to scorch the grass by overdosing.
- It will stain carpets, patios and clothes etc.
Alternatives to Lawn Sand
Lawn sand isn’t as popular as it once was because other “all-in-one” products achieve the same results. Also, for lawns with moss and weed infestations, many dedicated treatments are more effective.
To get rid of moss, we recommend products advertised as “no rake” as these contain bacteria (Bacillus subtilis) that eats away at the moss while leaving the grass unharmed. There’s no need to remove the dead moss after using this product, and it won’t turn the moss black either. As the moss disappears, you just need to overseed, so the new grass fills the space.
For lawns with multiple problems, there are dozens of “all-in-one” products that kill weeds, control moss and feed the lawn; many are effective or even more effective than lawn sand and are best suited to more severe lawn problems.
Confusion With Lawn Levelling and Other Types of Sand
Lawn sand is used specifically to control moss and weeds and can, after repeated applications, help with drainage.
It shouldn’t be confused with top-dressing, which is often used to level out any imperfections in the lawn surface and improve the texture of the soil.
For example, lawn sand is applied at a rate of no more than 150 grams per square metre, while a topdressing mix of sand, soil, and compost is applied at around 2-4kg per per square metre.
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