Forum home Problem solving

putting new topsoil onto clay

Hi there. Fairly new to the garden!  Need information on how to turf a fairly large area of garden. Recently had a contractor remove a few tons of stone and rubble at the side of an existing raised lawn(that is well drained and dry) and wanting to extend the lawn. I have unfortunately started the work with no real knowledge of what to do! have had 9 bags of topsoil delivered and laid it over the area in question which was nearly all clay and after all the recent rain the whole area is now like a large container of soil soup. Comments from you all would be very welcome. I am a reasonably fit 70 year old and want to do the work myself. 


  • Allotment BoyAllotment Boy North London Posts: 5,004

    Where to start- You do not say how big an area you have so it's hard to picture. Unfortunately just putting a thin layer of soil onto compacted clay will not work. Should have got contractor to dig or rotavate, after clearing. you would need a depth of at least 4 inches of the topsoil to stand any chance. Try RHS website or Lawnsmith website they have information on all lawn related things including ground preparation.

    AB Still learning

  • PosyPosy Isle of Wight.Posts: 3,224

    This could be a bit of a problem. I'm not quite clear about what you mean: is the raised lawn now above the cleared ground? How much depth of ground do you need to add to level it or will there be steps between the old and new lawn? What happened to water landing on the cleared area, did it pool there?

    Clay is difficult to drain. The first question to resolve is where you want the water to drain TO. For example, will it run down towards your house? Is there a channel below the new lawn along which it can run off harmlessly? Are you hoping the water will just soak away into the ground as it falls? Is the old lawn well drained because all the water runs onto the part you have just cleared?

    If water is running off your lawn onto the cleared area, you may need professional advice about making drainage, it's engineering rather than gardening. If you just want to improve the clay because the garden drains well then you really need to dig your clay, breaking it up, preferably to about 12 or 18 inches. I would want to dig grit into the top 6 inches and then add topsoil. It will be hard work I fear.


  • FairygirlFairygirl west central ScotlandPosts: 46,349

    You need to improve the drainage. Loads of manure and grit dug into the clay before you add any soil. Adding compost as well will help - it depends just how heavy the clay is. You can't really add too much of those three things.

    Mix well into the clay to get a better medium before adding topsoil. 

    It's a place where beautiful isn't enough of a word....

  • davectdavect Posts: 2

    Thanks for the reply! Realise might need pro help, will keep posting info based on replies, thanks again!

Sign In or Register to comment.