Improving clay

The question of what to do with solid clay comes up so many times that I thought I would show some pictures of what I have been doing.


I have just started to sort out my front garden. It was largely paved with crazy paving, and underneath the clay was absolutely solid. It had certainly not been dug for at least 30 years. First job was to clear the site - about 25 feet by 20 feet.


The stumps took quite a bit of getting out. I dug a trench round them and undermined them like mediaeval castle walls. Doing it that way left no roots at all. The whole area was dug over deeply, using a post hole spade. My stainless steel spade is so pathetic that it bends like a cheap tin tray. But the post hole spade was very strong. It's several inches deeper than a normal spade and only about 4 inches wide. It's also very curved, which imparts a lot of strength, and because it only has a small base it much easier to push into the ground. The result was that digging over the site, removing stones and roots, was not so hard - but still tiring.


What clay really needs is plenty of manure and organic matter. I discovered there is a local riding stables nearby that is happy to let you take manure away for nothing - except a contribution to their disabled riding fund. Many trips resulted in the best part of a ton of manure.


Clay doesn't drain because the clay particle size is so small - about one ten thousanth of the size of a sand particle. The small size doesn't leave any patheways for the water. So it also needs plenty of grit to break it up. The ideal stuff is agricultural grit, which my local builder's merchant said they could specially order but it would cost �£70 per ton. However they could supply 10 mil gravel or sharp sand for �£36 per ton delivered in a disposable bag. Anything you add must be sharp, so it won't compact down, and not rounded. So the soft rounded builders sand is no good, but sharp sand is good. 10 mil gravel (not 20 mil, which is much larger) is also pretty sharp and almost as good as agricultural grit. So I ordered a ton of gravel and a ton of sharp sand. Two tons sounds a lot, but the site would easily have taken two or even three times as much.

Organic material, like manure, is not really a fertiliser - the level of nutrient is pretty low. But it is an excellent soil conditioner. Not only does it hold moisture but when organic material breaks down it binds the clay particles together to make bigger particles - and hence better drainage. Newspapers are organic, so it was an opportunity to dig them in as well.

 

I pondered for a little while as to how to dig in a pile of papers. it would have taken far too long to have torn them into strips. Then I remembered the old system of digging trenches. I decided to dig 10 trenches nearly two foot wide. So I split my newspapers into 10 small piles. For the first trench I threw the spoil to the right of the picture. Then for the second and subsequent trenches I threw it all back to the left, filling in the previous trench. The trenches were about 18 inches deep. I lined them with the newspaper, four or five copies deep, and then gave them a good soak with the hose.


Once you have got a trench you might as well put everything you can in it, whether it is fully rotten or not. So I added another 60 bin bags of my own compost in various states of decay. And today I just finished the last trench. The ground is now about 12 inches or more higher than it was,but it will settle back over the winter. Tomorrow's job is levelling the site, as there is surplus soil on the road side that needs to be used to fill in the last trench. There was no special mixing. The manure, gravel and sand was spread evenly on the top, then the action of digging the trenches mixed them all together.



I haven't really decided what to do with the site yet. I will probably leave it fallow over the winter, to allow it all to rot down. I will keep hoeing it to remove any weeds. I will probably have some gravelled area, but mostly it will be planted with perenials in a similar fashion to the picture above of my back garden about a month ago.

 

Looks like your on the way to some very nice soil!

See if you can find a local sand suplier, builders merchant charge the earth were as I can buy stone dust or sand at around �£15 per ton including vat (collected)

 

You have worked really hard there mate, hats off to you. Is that the top end of Harrogate you live in, I am sure I recognise the housing from when I did a project at Natwests huge call centre near there.

 

Well done Peter it's going to be worth all the effort look forward to seeing it planted.

 

Peter. Can I have your autograph? Talk about hard work. You've just managed to put me off gardening for life. Snooker is my new relaxation.

 

wow Peter, hows your back Great job. DEE

 

Thank you all for your kind comments. It was quite hard work, and I was slowing noticeably at the end! But, of course, its the ideal time to do it. Only when you first start do you have a blank canvas. My garden at the back is now quite well established, consequently it is much more difficult even to manure it or mulch it, because you are always disturbing something.

 

That was a big job to take on, Peter - congrats on a job well done!

Now you can have the fun bit of planning, buying and planting. :D

 

Peter you have been busy how long from start to finish were you at it and did you have any help?

Seems like an awful lot of work but then most jobs in the garden are and I'm sure you don't need to add any more stuff to the soil for a great many years.

Brilliant start for your plants but maybe not for your poor old back :(

Good luck when you get round to the 'fun' part of planting and remember we want to see pictures!
Helen.xxx.

 

Hi Helen - no I didn't have any help. I took about three weeks in all. I took it very slowly especially at the beginning, fitting small amounts of time in between other things. But as it went on I spent more time on it. The last and perhaps hardest part didn't take that long. The two tons of gravel and sand were delivered at 9.30 am, and spread by 11 am on Thursday morning and I had trenched half of the site in the afternoon, finishing the rest on Friday. Sat and Sun off, then I levelled it today (as I was trenching it, more soil tended to end up at one end). And this afternoon I planted a few token plants. I am going to leave it fallow over the winter to let everything rot down. Some of the manure was not that well rotted.

Yes Dendro - now hopefully comes the fun bit. I am not really going to buy many or even any plants - that could cost a lot. I am going to treat it as a dry area, as it gets full sun almost all day, and I don't wish to water it. I haven't decided what to grow yet. I'm looking for suggestions. But I have potted up 220 self seeded seedlings of Centranthus. Mine started to flower in April and its still in flower now and quite happy in dry soil. I have also taken 30 cuttings of Perovskia (Russian sage). I have other things that like it dry, but the problem will be to build up a quantity quickly.

 

Wow, peter, i take my hat off to you. If i had one

My coping with clay was really pretty naive now from what i've read since. All i did was fork it lots the first year and dig it over. Stupid me. Now though 2 years later, i have added loads of organic matter and drains really well.

We used to get really bad water logging. So thats an excellent idea of laying newspaper down there too. I did that as my last phase in spring this year. I laid lewspaper on top, with grass cuttings. When it dried, i forked it all in.