waterlogged sunken bed


as a follow on from my thread last week about improving heavy clay soil, at the weekend i spent most of the 2 days digging up LOTS of HEAVY(!!) waterlogged clay, about just above knee deep, digging in LOTS of sharp sand (x10 bags of this stuff: http://www.diy.com/nav/build/building-materials/aggregates-cement/standard_bagged_aggregates/B-and-Q-Sharp-Sand-Natural-Large-Bag-9273145?noCookies=false) as well as gravel/grit.

im not sure if anyone else around the country had the same weather but during the afternoon on saturday we had thunder, lightning, hailstones, blustery winds and to top it off lots of heavy rain for most of the rest of the day! after the downpour, and half way through digging, as some of the soil had compacted from me standing on it, LOTS of water gathered on the surface, it was like a bloody pond. i manually removed TEN BUCKETFULS of water of the surface of about 3m sq. area image




the sunken area you see used to have a shed there, and it's on a slope, which is why the water has accumulated at the end of the grass.

my question is now, im really not sure what to do with this area. the consistency now of the soil in that area is like cement, all squidgy and splodgy. its one of the sunnier places of the garden and my preference is to have a raised bed there, but im not quite sure how to go about it and ensuring that it doesnt get waterlogged constantly image ?



  • Busy-LizzieBusy-Lizzie Posts: 12,091

    If it had a shed there are there concrete foundations underneath stopping the water draining away? It may be that the ground is just too wet because of all the rain this winter and will be better later. Have you dug in any compost? Compost and manure are better than sand for improving clay.

  • I have had the same problem with parts of the garden as my house is a new build.

    Large rocks, clay and everything else was buried in my garden and what I did was clear the lot out hundreds of bags of clay and large pieces of rubble.

    Top soil, compost ( 20 x 75 litre bags ) soil conditioner  were all added and now my soil is perfect.

    This was not a job just for the weekend it took me weeks to do it and the area I did was 32 feet long by 6 feet wide.

    You may need to check the soil what the lawn is on as well.

  • djjjukdjjjuk Posts: 212

    Busy-Lizzie, no i pulled the concrete up at the time of removing the shed.

    dannyboy, the whole lot is heavy clay. i would prefer to build the surface back up from the sunken bed to the same level as the surrounding grass. that particular area (lets call it the pit) is about 1.2m across by about 2.4m down - and about 15cm deep. 

    after you dug yours up, what did you do with it after? did you compact it all, or wait for it to settle and level itself? im not really sure what the best thing to do is. the ground is still saturated so its probably not the best time to do anything with it?

  • djjjukdjjjuk Posts: 212

    uh oh ... been reading some different articles and information about this this morning and it looks like i might have made a big mistake adding sharp sand ... as it has gone cement like it might have made the problem even worse! think to alleviate the only thing i can do now is dump lots of soil conditioner on it and dig that in as deep as possible image

  • DovefromaboveDovefromabove Central Norfolk UKPosts: 43,615

    Wet soil is best left well alone - let it dry out - it will do eventually, then you can have a look at the structure and decide what to do - it probably does need some organic matter dug in to improve it - but at the moment, in the extremely wet conditions we have this year, I would advise against any digging of wet soil. 

    It might be that you need to put in a land drain to a soakaway or something like that - but on the other hand it might just be a short term problem resulting from this rather freakish weather. 

    No-one knows if you've done your housework, but everyone knows if you've done your gardening !
  • djjjukdjjjuk Posts: 212

    with hindsight dove i probably should have left it ... but i was keen to get it sorted as best as possible before spring so i could plant in it. i really dont want to have to delay another year, and as clay is constantly more or less wet anyway in all but very hot weather, especially deeper down, i would had to have faced this task at some point ... might as well do it sooner rather than later. its been unfortunate that the last couple of weekends have been more or less rain non stop. i havent seen the forecast for the west mids but i really hope, and NEED, it to dry and warm up a little ..

  • FairygirlFairygirl Posts: 19,717

    I understand your keenness to get on djjjuk but as you've found out some sand can unfortunately make the problem worse. My  garden is heavy clay and had very few planted areas in it when I moved in last February, so I constructed raised beds - even 6"  or 8" can help. As others have said,  well rotted manure and compost, as well as grit, are the best soil improvers, but it can take a while to get the beds in good order. The rain this winter has made things worse so it would be better if you could leave the digging for a couple of months.  Once you get some plants in it'll help too, and if you add some grit and compost whenever you plant anything it helps the soil enormously over time. image

  • djjjukdjjjuk Posts: 212

    Hi fairygirl. the main area i want to use for now is a border around the whole garden - inbetween fencing and edging of the lawn. that is around about 50cm or so wide, and about 4m long. the problem came about after demolishing the shed. there was no edging surrounding it and with the shed being on concrete slabs, removing these left a little bit of a sunken bed that was lower than the grass by about 15cm or so.

    the whole area is on a slight slope aswell, so whats happened is the compacted clay under the old shed, couple with it being lower and on a slope, has meant any rain simply floats on the top of that pit and accumulates at the wall where it meets the grass. maybe i should just turn it into a pond!!

    the current border has gravel to about 2 inches or so, which i want to remove so i can plant in it. but as its heavy clay and what i want to plant needs good drainage - that does not compute, so ive attempted to alleviate that by digging in this sharp sand .. i havent dug manure/conditioner or compost in it yet, but have some ready to do so at whenever the best time to do it is.

    also FG that area is just totally unplantable for now. it is about a foot deep of cement like structure of clay and sharp sand. i assume the best thing is to leave it to settle.

  • DovefromaboveDovefromabove Central Norfolk UKPosts: 43,615

    An old country name for February is February Fill-dyke - meaning that it will be wet, whether because of heavy rain or melting snow.  February is the time for planning - not working your garden.  The old country gardeners will tell you not to walk on the soil when it sticks to your boots.

    No matter what the soil is like you do not need to be working on it in the wet - you will do more harm than good by breaking up the structure and compacting the clay subsoil. 

    When it begins to dry, hopefully in March, you can dig in some organic matter - garden compost and/or well-rotted farmyard manure, and grit if it needs it.  

    For now the best thing you can do is make a compost bin and start to make compost if you don't already do it, because clay soil needs lots of compost - the rest of the time don't feel guilty, enjoy sitting down with your seed catalogues and gardening books and conserve your energy - you'll need it later in the year image


    No-one knows if you've done your housework, but everyone knows if you've done your gardening !
  • FairygirlFairygirl Posts: 19,717

    I'd agree with Dove. I moved a shed last summer, as I've opened up the existing garden, and the area it was in has the same problem. It will become part of a new lawn but at the moment resembles the Somme. I avoid walking on it - a strip in front of a new raised bed has a few slabs on it for access to the  rest of the garden, but I'll leave the preparation of that whole area until spring when it will be more suitable. You say you have some manure and compost already, so it may be worth putting that down onto the area where the shed was and wait until it's more suitable to work on. By then, time and nature will have done  half the work for you. image

Sign In or Register to comment.