Founded in 2008. The Landscape Juice Network (LJN) is the largest and fastest growing professional landscaping and horticultural association in the United Kingdom.
LJN's professional business forum is unrivalled and open to anyone within within the UK landscape industry
LJN's Business Objectives Group (BOG) is for any Pro serious about building their business.
For the researching visitor there's a wealth of landscaping ideas, garden design ideas, lawn advice tips and advice about garden maintenance.
Replies
Clay is clay unfortunately. Short of installing land drainage, you've just gotta live with it - waterlogged in winter, baked dry in summer.
I'd be hesitant of laying turf on clay with sand. Unless it's well worked in I think you risk simply forming a 'cap' on top of the clay. Compost would be better for getting into the clay and breaking it up, but that is long term and if you are only thinking of putting a layer down under the turf simply won't be enough.
You can have a very good lawn on clay, I maintain a very large lawn on heavy clay, you just need to work around the soil conditions. The customer now wants a croquet lawn and we are looking to install land drainage for that.
Perhaps go down an agricultural route to see if any methods or additives can provide a solution to help break the soil down .
From memory but its vague there used to be an absorbic organic chemical which could break down clay to prevent it from binding .
Ditches also provide some drainage and allows run off but the clay surface becomes crazed baked by heat and compacted , I dont know if you could guarantee success if the clay is so heavy .
In one area i worked which was clay they wanted an ornamental lawn and flower meadow it was a huge operation involving tons of topsoil which was seeded and very successful until the rain penetrated the surface and reached the clay base , so then soakaway crates filled with gravel had to be installed and weeping willows were planted to soak up the water .
There was still run off towards the property but the land sloped towards it .
The actual lawn established itself but the customers were realistic about the negative aspects but other customers expectations might be unrealistic and it turns into a job which gives you sleepless nights , not worth it in my opinion
I have the same problem, a small estate garden - the lawn was awful, over the summer we have got rid of the weeds, we moss killed, scarified and reseeded about a month ago - there wasnt a lot of grass left. I went back this week and it is just clay with more moss on it :( :(
As I see it the options are remove a layer of clay and replace with top soil, then turf (expensive) or just put turf on the clay, and pray.
I personally love clay soil! To improve it I needs lots and lots of sharp sand mixed in, it really opens the soil.
Where is it wet? Is there water run off from paving that can be diverted? Could there be a pan in the soil from heavy machinery? How big of is the area? To break a pan in a lawn I use a 6ft digging bar to break through the pan into the bed rock and then stuff the hole with sharp sand or grit. You can feel the pan with the bar.
Agricultural Gypsum can be used, it makes the clay granules turn into larger particles more like a sandy soil. Can be bought in 25Kg bags for £20 or less
Soil improver can help but it needs working into the soil plus some sharp sand and horticultural grit. That would improve the soil structure and improve drainage. Failing that if you put a layer of brought in topsoil on the clay then if it was of a sufficient depth I think you can have a successful lawn.
The results depend on budget and expectation. The above garden was compacted modelling clay on a new build. We removed the top soil - what little there was of it and installed a full drainage solution complete with sump. 17T of gravel around the pipes set out with no more than 8ft distance between them. The results have been great. No more flooding unlike their neighbours BUT even with this in place they can till not walk on the grass in Winter. The soil is still clay as we could not afford to replace it and still holds water even if it is two inches thick.
The second way - which is temporary- is to create a new memory in the soil. We dug off the top soil and using a digger turned over the subsoil 600mm deep. We then rotovated it and added lots and lots of manure and then relaid it. Again great results as it hasn't flooded and the grass looks great BUT it will compact over time and then it will be an issue. The organic matter helps with drainage by stopping the clay plating. However again, don't walk over it when it is wet. Cheaper than a full drainage solution.
The third way, as they wanted to use the garden all year for football training was to install artificial turf. I'm not a fan but under the circumstances, it was the only solution. I would rather have grass on clay than plastic any day of the week.
I have tried sand but it never seems to work that well. I recommend organic matter and address the drainage issue. I echo the other comments that no matter what you do it will never be great and advise your clients not to walk on it when it is wet as it will compact and will hold water again.
+1 with not using sand to try and break up the clay, it never works, far better using organic matter.
Messy! Triple French drain leading to a main outlet if indeed you have somewhere for it to travel and the angles permit – 12 inch holes filled with sharp sand all around the build will help. Good luck!