How much topsoil over gravel to grow grass?

Question

We've got a section of garden with compacted gravel underneath. Can we lay topsoil on top and get grass to grow or does the gravel need to come up first?

Gem · Accepted Answer

It will be 4 to 6 inch on top of the gravel to grow grass

Curtis · Answer

Yes — you can usually grow grass over compacted gravel, but the depth of topsoil is what makes the difference.

For decent grass growth you generally want:

* 100–150mm (4–6 inches) of quality topsoil minimum
* 150–200mm+ if possible for a healthier lawn long term

If the gravel is heavily compacted and doesn’t drain, it’s worth breaking it up first with a rotavator or fork. Grass struggles when roots hit a hard layer straight underneath.

A few things to check first:

* If the gravel is only a thin layer mixed into soil, you can often leave it.
* If it’s deep hardcore/crushed stone from an old driveway or patio base, removing at least some of it is better.
* Make sure water can drain — standing water will ruin the lawn.
* Add screened topsoil and lightly compact before seeding or turfing.

Best setup would be:

1. Loosen/break up compacted gravel base
2. Remove larger stones
3. Add 4–6 inches of topsoil
4. Level and compact lightly
5. Seed or turf

If you’re turfing instead of seeding, you can sometimes get away with slightly less soil, but thinner soil dries out quickly in summer.

Thanks
Curtis
WB LANDSCAPING

Andrew · Answer

I would take stones up first ,rotavate the soil thsn add topsoil if necessaly

Martin · Answer

Ideally you would clear the gravel away hard question to answer as I don’t know the ground but minimum 100mm

Victor · Answer

Yes as long as you have enough depth to put soil on top,
It will help with drainage, good luck 👍

Mohammad · Answer

First, we flatten the rough ground and remove a lot of sand, and then I pour the soil.

Joseph · Answer

It's always better to remove the stones as when the grass comes up u can cut it with your lawnmower

Graham · Answer

You can lay topsoil over it and try to grow grass, but if there’s compacted gravel underneath it’s never really ideal long-term. Grass needs a decent depth of proper soil to root into, and when you’ve got tight gravel below, water tends to run straight through in places which leads to patchy growth, weak roots and it drying out in the summer.

From a job point of view, the proper way is usually to strip the gravel back and remove it if it’s not too deep, or if it’s well compacted and thicker, break it up as much as possible, level it off properly, then bring in a good layer of topsoil (normally at least 75–100mm for turf, more if you want it to establish well), then seed or turf on top.

If you don’t want to dig it all out, you can sometimes get away with topping it with enough soil, but it needs to be a proper depth rather than just a thin layer, and results can still be hit and miss compared to doing it properly from the base up.

Rod · Answer

Soak area first realy well. You should lay 175mm of top soil. Check ph of soil if adding ph 6 is suitable. After laying soil compact gown to 150mm. Grass roots grow six inches. Soil should be a good grade containing 6mm grit and organic materials.  Before laying turf soak again so water sits on top. Then leave for a day and then lay turf. Soak turf well

Daniel · Answer

I would not recommend it 🤔 to be honest with you it will not last the year

How much topsoil over gravel to grow grass?

Follow Us

Cookies

Manage Cookies

Essential cookies

Analytics & Tracking

Advertising