What topsoil is best to level a lawn, when you have clay soil?

[jtravers5]

I’ve got a gardening conundrum which, after many hours of surfing the web, I have been unable to solve and was hoping you might be able to offer some pearls of wisdom please

Task is to top dress our lawn as it is very uneven.

We have clay soil.

Problem is what type of topsoil to buy. I’m guessing that we will need 1-2 500L bulk bags .

I’ve read that you should avoid adding sand to clay soil as it can create a concrete like mixture & lead to poorer drainage. So it puts me off using top soil which has got sand in it. However, all the ones I’ve seen online though have sand in it.

However, I’ve also read that organic matter on its own, isn’t suitable for levelling a lawn.

So it feels like I’m stuck between a rock and a hard place.

Do you know of any solution?

 

[cpp gardener]

The best soil to use is the same soil you already have. Putting a layer of anything different on top creates a layer that water won’t move from until it is saturated. This is called a perched water table and causes lots of drainage problems.

 

[oneeye]

Hello and welcome friend. The only problem with using top soil is that weed seeds can be mixed with the soil and can introduce an infestation of weeds into your yard. Plus the top soil may not match when it comes to soil chemistry. If you want to take a chance on top soil it would work for leveling but may cause other problems.
Amending your soil properly every year can overcome heavy, compacted clay and get it back on track for healthy lawn and garden growth. Adding materials like organic compost, pine bark, and composted leaves and gypsum to heavy clay can improve its structure and help eliminate drainage and compaction problems.

 

[Nightshade Family]

I’ve got a gardening conundrum which, after many hours of surfing the web, I have been unable to solve and was hoping you might be able to offer some pearls of wisdom please

Task is to top dress our lawn as it is very uneven.

We have clay soil.

Problem is what type of topsoil to buy. I’m guessing that we will need 1-2 500L bulk bags .

I’ve read that you should avoid adding sand to clay soil as it can create a concrete like mixture & lead to poorer drainage. So it puts me off using top soil which has got sand in it. However, all the ones I’ve seen online though have sand in it.

However, I’ve also read that organic matter on its own, isn’t suitable for levelling a lawn.

So it feels like I’m stuck between a rock and a hard place.

Do you know of any solution?

Hi there! That’s a really great question, and you’re definitely not alone—top dressing clay soil lawns can be tricky.


You’re right to be cautious about sand. Adding sand alone to clay can indeed make things worse, essentially creating a brick-like texture that hampers drainage even more. But when mixed properly, sand in combination with compost and screened loam can actually help improve structure over time.


For your case (levelling and improving soil health), I’d recommend looking for a lawn top dressing mix that contains:

• Sieved loam (soil)
• A small proportion of sharp sand (not builder’s sand!)
• Composed organic matter

This kind of mix is often sold specifically as “lawn dressing” or “top dressing mix” and is designed to level uneven lawns while still being clay-soil friendly. The sand improves workability and drainage when the loam and compost balance it out.


If you're unsure about the pre-mixed options, you can also create your own:

• 40% screened loam
• 40% composted organic matter
• 20% sharp sand

Mix thoroughly before spreading a thin layer (~½ inch) over the lawn, brushing it in with the back of a rake or a lawn lute.


Also, just make sure the lawn is actively growing (spring/summer), so the grass can grow through the top dressing more easily.


Hope that helps, and good luck with your lawn!