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Clay soil drainage issue


I have a clay soil garden with a lawn that does not drain the water away even though I have had herringbone drainagepipes installed. would rotovating the clay with sand help? 

My garden slopes left to right and from the back fence towards the house. The water standing on the soil at the boundary of my fences and nearest the house next to the path. Can you give me advice would it be better digging trenchand with catch basins because the herring bone drainage has not seemed to work anymore after two years. 

Please help.



  • Try the good old way of using a fork or shoes with spikes on, then use sand brushed over the fine holes, keep this up for as long as you can.
  • Dave MorganDave Morgan Posts: 3,123

    Rotorvating won't solve this issue Monty, the drains you installed weren't installed correctly as it should have caught the run off which is what your'e suffering from. Drains near the house is what you need properly installed they should take care of the problem. DONT add sand, you'll end up with soil like concrete is you do which will make things worse. This is very different to drainage in a FLAT garden, it's different engineering.

  • Hostafan1Hostafan1 Posts: 26,165

    course grit and lots of organic matter like well rotted farm yard manure, or garden compost. You need rough bulky material, not sand.

  • Yes sand will just bind into the clay .  I had intractable clay at the previous property, found best thing was to order in some bulk spent mushroom compost. Mushroom growers are always looking to dispose of the used compost and as it is rotted straw manure and friable soil is quite light to handle and very fibrous . Got a few mushrooms the following year to boot.  Dig 3" layer into the top surface and the worms will do the rest.

  • GemmaJFGemmaJF Posts: 2,283

    As above but I would go for the 'long manure' that is the stuff with straw still showing in it for drainage. Though any of the organic materials mentioned will help stop the clay binding and compacting which must help with drainage.

    If it is practical dig off the top soil, double dig incorporating the grit (I would avoid sand totally) and long manure. Rotavate that in and replace the top soil. It will need to settle for a while of course before you can get a flat lawn. 

    I re-profiled my entire back garden to drain away from the house. Being on London Clay it seemed with a couple of wet winters it was always standing water. The trouble being how deep is the clay? Whatever drainage you have, where does the water go? It is not always simple to solve it.

    If the predictions are to be believed we are in for many more mild wet winters so I thought in the long run the immense effort required to change the slope in my garden would pay-off. 

  • MontyMonty Posts: 4
    Thank you very much for all the advice. Looks like I will just need to put a lot of hard graft and dig up the drainage pipes I had installed because they are not working and add in the grit and manure to see if this will solve the problems .

    The issue is that the garden slopes towards my house but work with what you have I suppose .
  • Monty.

     Before you dig the drainage pipes up. just ask "does the water collected have an outfall " .  i.e. where does it go to ? fine to put pipes in to collect it but does it have anywhere to go when it is collected ? . For it to work it needs to drain to a sump and then outfall to something that will take it, say a ditch or a better drained area of the garden, a soakaway providing you are able to construct one that will work  or as a last resort a small submersible pump to chuck it off site. Just putting pipes in with no outfall  will do nothing.

  • I have some of this arriving tomorrow which should go a long way to dissipating water on heavy soils. if anyone would like to try it for free let me know.

  • Tropical SamTropical Sam Posts: 1,493

    I have heavy clay and a sloping garden and we use a French Drain to soak away and never get standing water for more than a few minutes after heavy rain. The French drain and adding humus into the soil as per the above has helped a lot. For the lawn I spike over it, esp where it becomes compacted.

    Can you add a small ditch next to the path? That should help dry out your side - standing water is never good. I would then decompact it and add air via the humus.

  • BoaterBoater Posts: 241

    I'll re-iterate the advice to consider where you are draining too - if you are on a hill it will probably just keep moving down and become someone elses problem (unless you are close to a river), otherwise you are just movign it around your garden.

    When I was a kid my dad built a soak away for rainwater drains in the paddock before he turned it into a veg patch. 8' x 8' x 8' hole into mostly clay, backfilled with several tons of rocks and then some topsoil put back on top. Then he built a network of concrete paths and bought a couple of lorry loads of topsoil - I earned my pocket money one summer rotavating the clay based original topsoil and then shifting the new topsoil from the front garden to the paddock. Rotavating clay is extemely hard work.

    Er, the main point was that the soak away worked OK, the veg patch was never waterlogged even though all the house gutters were drained to it.

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