Clay Soil

Unfortunately there is no short cut to improving soil structure. With clay, if it's poor draining you should add horticultural grit. To open up the structure add plenty of well rotted organic material. For sowing fine seeds you may well want to get in a bag or two of sterile topsoil and put a layer on the surface deep enough to sow into.
Good luck, once the soil has been improved over time you'll have a fertile and rich growing medium. One bonus of clay soils is that nutrients don't leach away as fast as in sandy soils.

Grit - sand - coffee grounds - anything organic - just add to the mix. Cardboard, paper and plant through holes into the clay - putting compost at the bottom of the planting hole.

I got good results last year from digging patches of the clay at our lottie, mixing with compost and coffee grounds, and sieving back in to the hole. Was really good for carrots/parsnips [I only did the beds that I was putting the carrots/parsnips in] - nice long straight carrots and when we dug it over this autumn, the soil had greatly improved in just a few months.

For spuds, we dug quite shallow holes for the seed potatoes [it had been rotavated] and once the foliage started growing, put 3 sheets of newspaper over the foliage [with a hole in the middle] and used home compost to earth up rather than the clay. Again, it got dug over when we harvested and just adding this little amount of organic has improved it in a short space of time.

We also grew some things such as brassicas, corn, sunflowers through holes in cardboard, the cardboard held down with lumps of clay, and it has rotted down and has opened out the clay nicely.

i can't recommend coffee grounds highly enough - the caffiene has already gone and you are left with and organic addition that really helps 'cut' the clay as you go - it really helps open up the soil.

And doesn't Gypsum also help - you'll have to look it up but from my soil engineering days I seem to remember that it can help if you need it doing quickly.

ETA: http://www.rhs.org.uk/Advice/profile...imingsoils.asp

Liming helps clay soils - but don't lime where you are going to plant your spuds...save the home made compost/manure if you have any for that bed.

Green manures are a cheap way to improve both the structure and nutrient content of your soil.
Grow for at least six weeks, and then chop down and dig into the soil. They are a great option when preparing new land for use – some varieties, such as lupins, fodder radish or alfalfa, even help to give the soil structure because their fibrous tap roots break up the subsoil.
Field beans and grazing rye are excellent in clay soil.

I suppose it depends a lot on just how dense your soil is. Mine is a solid clay table, and I tried for 2 years to get it down to the fine tilth I wanted but in the end I just gave up and built raised beds. Cheating I know, but now I can at least grow things properly and know that the soil will turn over at the end of the season and the beginning of the year.
I dig the beds over at the end of each growing season, and make sure I get down at least one spade depth into the clay soil, to try and increase the depth of my beds.
I filled my beds with a lot of horse and chicken manure, as well as normal composted green matter, and finally this autumn, I did notice an improvement in the bottom layer of my beds. Its taken its time though.

We really really hate it when that happens. It's never happened here but it does really p#ss us off when a peice of land (or an 'out of business' farm) gets bulldozed to make room for yet more ugly council houses.



Anyway...clay soil. We have clay soil here too. It took some hard work to get it right but it is OK now.

Drainage is what you need to improve. What we did was to break up the clay soil using a rotavator (don't do it by hand unless you are used to having sore hands and a very very bad back).
Once the soil was broken up we added loads of normal multipurpose compost to it and dug it over again. We also added some horse manure from our local stables.
Then we added some very small grade grit and some sand to it and dug it over again.

The soil is now good and we have had good crops from the veg beds we have.

Each year we top the soil up with more compost, that we make ourselves, and dig it into the beds.

Thanks for all the replys so far, some really good ideas I hadnt thought of especially the Gypsum. I remember now that one of the old boys who were on the site telling me about it when we moved in 25 years ago but the plots were so well cultivated that I never needed it.

Trouble is that the little piece I have now is in such a state that I had to double dig it,hence the clay.

Mike and Louise.

Our local council really are little treasures. The land was originally given to them at the start of the war by a farmer with a covenant attached to it that it only ever be used for leisure purposes. They managed to find a way around it, the Allotment Association fought them right up to the High Court in London but lost. Lets just say the council forget to disclose certain things that would of swayed the case.

They have allocated instead the worst piece of ground they could find in the borough for allotments. At the moment I am about 250th on the waiting list.

Alan

Zazen, thanks for the tip about the coffee grounds - that's something I never knew.

Makes you sick doesn't it.
It's even worse when the city, town or village you live in doesn't have enough greenery around as it is. And what greenery there is gets used for housing.

I feel sorry for the people who lose an allotment and either can't get another one or don't have a big enough garden to carry on thier rewarding hobby.

No problem. I spent 14 years as a soil engineer so learnt a thing or two about clay in all it's glory. It really is a wonderful base, you've just got to cut it with granular and organic to break it up a bit.

My plot was clay....no topsoil (the farmer niched that) just clay so it was either the Somme or tesco carpark.

I have had it 5 years added, 20 ton of manure and coucil compost. 5 ton of sand, and 20 bags of grass cuttings a week in the summer and all the leaves I could find. Plus planted potatoes every other year.

And its now......well like the somme in the wet and tesco carpark in the dry.

i'm starting to see a pattern in this thread and wonder if anyone knows a good pottery teacher as im on clay too......uncultivated for 20 years?
glad i went for the raised beds

soil help needed

Hi all well after that snow has gone I finally got down to the task of digging the plot over for the 1st time. I pulled the big root weeds out and grass.

The help I need is its very clumpy soil clay and it doesn't break up at all a hard dig I will say.

Anyway got the big weeds out but thought of Lime but unsure if you can get it anymore or maybe grit sand.

I am new so if the two ideas are silly well its because I am new and need help on making the soil better.

I await your comments.

Clay is basically small gritty soil particles like sand, but with a different chemical structure that makes them clump together in microscopic lumps glued together by a tiny membrane of moisture, and excludes air and a higher percentage of water than most soils. I don't have clay soil myself and I have never had to work any, so all I can say is, the recommended procedure I've heard of for improving clay soils is to add humus. In other words, add as much decomposing plant fibre as possible; as it breaks down the chemical bonds that tie up the particles and their nutrients will dissolve and the soil will become more spongelike for both water and nutrients.
That said, I just looked up a book and it said liming has the effect of chemically breaking down the particles, so I'd guess that's a more temporary quick fix and the humus is a slower, more permanent one.
You can still get lime; agriculture would halt without it ! There have been various threads on here about it even within the last week or two, it pays to shop around as it can be quite expensive but you can get it cheap through allotment shops for example.

Also, clay soil is often alkaline, and liming will exaggerate that, which might not be good for the plants.

Now you've got the weeds cleared, I would recommend covering the soil with a couple of inches of organic matter - manure, soil-conditioning compost, even straw - then laying down cardboard weighted with bricks or water-filled soft drinks bottles. I would suggest planning permanent beds, too, so that you don't walk on soil that's been loosened and improved, and thereby undoing all your hard work.

If you haven't got enough of this sort of stuff to do the whole plot, do as big an area as you can and cover the rest with black plastic - the supermarkets usually get loads of it in cheap in the spring. Cover the path areas this way as well, or better still use the newspaper method described in the recent issue of GYO.

Let the spring rains and the worms attack the cardboard area for a couple of months, then plant it potatoes and squash through holes in the cardboard. They will break up the soil with their roots and their foliage will shade out weeds. Given time, you will create a layer of finer soil that seeds and young plants can go straight into.

BTW, I got all this from Charles Dowding's book "Organic Gardening - the Natural No-Dig Method" - worth a read!