Worrying state of my new lawn's topsoil
Hi,
I've just dug out my front garden, which was paving slabs. I took out the slabs and concrete and sharp sand and assorted rubble, bringing it right down to the underlying earth.
I did notice a bit of clay in some areas, but not all over, but maybe I didn't go down enough in those other areas to find it.
I've now spread 2 ton of top soil in the hole, and it looks like I need another ton to bring it to level.
So today I tried walking over the earth to compress it down, making it easier to see how much more soil I need. It has been raining in London these past few days.
I've found some areas are firm, but other areas are completely muddy and bog like. Is this because there is clay underneath? The area is 2.5m x 4m and I've dug about 20cm deep.
Is it going to be alright or am I heading for a disaster?
The end game will be a lawn of wild flowers and grasses left to grow all year and trimmed in November, with Roses/Jasmine growing up the front of the house...
Thanks for reading, any advice greatly appreciated.
Posts
James London is built on clay and its difficult stuff. It's not a big area but it's been compacted by the patio. You may well be better off removing the topsoil for the moment and breaking up the clay and mixing in grit or pea shingle. I'd say add manure but as you want wildflowers they won't like a soil that's too rich. My experience of wildflowers on clay isn't good. They really don't like the water content, they prefer drier soil. The only way to mitigate the rich soil and wet is by adding grit and sharp and I mean very sharp gritty sand. If it were me I'd forgo the wildflowers and go with plants more suited to your conditions.
Oh jesus, I've created a mud pit.
It's just rained and there's just puddles of water.....
Thanks Dave - here are my thoughts:
Whatever I do I need to fix this. I've just bought a 600mm drill bit so I can drill some holes and let it initially drain, then I'll dig trenches and maybe drill some more holes and fill with sharp sand and then cover over with the top soil but that mixed with sharp sand too.
How does that sound?
James, I would follow exactly what Dave has just said, drilling holes and filling with sand won't do it. It needs to be broken and mixed.
Ok, I can do that.
How deep will the clay go on for do you think, forever?
Most parts of the underground were tunnelled through clay James, that's how far it goes down. All you can do is go down a good forks depth, fork and a half even. Get the grit in. If you're not going down the wildflower route add as much well rotted manure as you can. Even go to the pet shop and buy straw to add to the mix. Get the topsoil bagged up and put it to one side for a few months. In a few months you'll notice a difference. It won't be perfect but you won't have a mud bath when it rains and you may be able to add the topsoil by then. If you have problems get back to us, always willing to help.
I get what you're saying Dave, but is there any point if I can't break through the clay? If I can't then the water will never drain away no matter how much drainage I prepare....
The one thing that gives me hope is right by the house the ground is quite dry, leading me to think the foundations went through the clay and there may well be an end to it...
I will wait until it's dry and start digging!
James the point is to create a barrier between surface and foundation. By that I mean a depth of decent drainage before you hit the clay beneath. Water drains through the top layer and then sits below the top layer and will drain naturally. Trust me it works even on heavy clay. So about a foot of reasonable drainage which will allow grass to grow quite happily and you won't get a bog when it rains.
Have a similar problem to deal with. I also have 'plans' to deal with drainage issues.
Another approach I am looking in to, is seeding with a grass tolerant to excess moisture around its roots.
The varieties most mentioned as suitable are 'Fescue' and meadow grasses. Anybody know better..._
Thankyou.