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New turf issue of pockets of mould.

Lawn relaid with new turf on heavy clay, sharp sand and compost in September but within 6 weeks small deep black spots of mould appeared under the adjacent grass. Ground quite wet. The problem seems to be growing over the weeks and we do not have pests or dogs. Any ideas please? 


  • DovefromaboveDovefromabove Central Norfolk UKPosts: 82,220
    Hi @nayd721ur8DNqs and welcome to the forum  :)

    I'm sorry but we really need a better photo to be able to see what's going on with your turf.  
    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • Hi. Thanks for that response. The close up photo I sent shows pockets of black slimy fungus scattered around the new turf more of which can been seen in the other photos I now attach  
  • Pete.8Pete.8 Billericay, EssexPosts: 9,863
    It looks like a slime mould.
    Not very pretty but quite harmless and will usually vanish in a few days.
    The 'body' of the mould is underground and the black goo are its 'flowers'.
    Once it dries the spores are released and it disintegrates and vanishes.

    Some info here-
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • Thank you Pete.8 - you are star and if I could I would raise to you Pete.1!

    I think our problem is that the installers recently laid the new turf on compost, on  sharp sand which was on top of clay without working the sand into the  clay thus leading to  waterlogging after recent downpours. 

    Will keep you posted on how we get on.  
  • FairygirlFairygirl west central ScotlandPosts: 49,086
    I was going to ask what the prep was like, and just how much sand/compost was used.
    Grass doesn't need a huge depth of decent soil in order to grow well, but if the clay is manky and not improved in any way, that's where the problems will arise, especially if you're in a wet area.
    You may find you need to do a fair bit of aeration in future.  :)
    I created a lawn here about 8 years ago [heavy clay soil, lots of rain] and I knew the prep would be key.  The 'garden' was mainly gravel and slabs. The advantage I had was that I could leave a lot of the gravel in situ, and worked in, to combat the clay. I did a raised edge and then filled with soil/compost and a good amount of the gravel. That worked very well. 

    I hope it improves for you, but I think you may find it soggy on a regular basis if you can't improve the drainage, especially if you want to use it a lot. Good luck with it  :)
    It's a place where beautiful isn't enough of a word....

  • Pete.8Pete.8 Billericay, EssexPosts: 9,863
    You're welcome @GodfreyD
    It does sound like you have a problem with drainage in that area.
    Hopefully as @Fairygirl suggests a lot of aeration with a fork will help.
    Good luck!

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • Thanks Fairygirl.

    Our neighbour had his whole lawn re-turfed at the same time on identical clay soil,  the only difference being is that our installer placed a shallow amount of sharp sand on top of it. The two adjacent gardens are now  materially different with his showing a lush level green whilst our is  pot marked in the way shown in the photos. Our installer refuses to return to check it out.
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