[theplotbegins]

We were allocated a new plot just as the hot and dry weather started. We have removed rubbish, weeded & mown. The ground is clay and set as hard as concrete with lots of cracks.

After lots of research including talking to fellow plot holders we're planning to use raised beds. Does anyone have any suggestions or recommendations for soil preparation?

Soil is a long term project but we'd like to "jump-start"  a couple of beds by adding topsoil and or compost in the hope that we might be able to start some winter veg this year.

Does anyone have any advice or recipes/proportions? There's no evidence to show which crops have been grown previously.

Many thanks.

[snowdrops]

Well rotted manure & composts. Look at no dig, cardboard to keep the light out, then at least 6 inches of well rotted manure, you might find that you don’t need the raised beds. Google it there’s a website for info. Charles Dowding is the chap that promotes it in the UK. Plus there’s a few on here that practice that approach. Clay soil is not all bad, holds on to the nutrients

[Plot 1 Problems]

As Snowdrop says, tons of organic matter is the key. I'm a semi no-dig grower, but I did have to bust up my clay first before I started adding compost to the soil. Depending on your fitness and enthusiasm I'd break the surface of the soil up with a fork or pickaxe before layering compost on. But then in this heat that might not be a great idea

[Goosegirl]

If you want to get a head start I'd double-dig the areas by taking out a trench a spade's depth and put the soil in a wheelbarrow. Fork deeply over the bottom of the trench and add manure, mushroom compost or whatever you have available, plus some sharp sand and grit. Dig the next trench by putting the removed soil into your first trench and fork in as above. Keep doing this until you've done the last trench then fill that with the soil from your barrow. Edging your beds will help to stop the soil falling onto the surrounding area. If you want some topsoil you need to get it from a reputable supplier. I like mushroom compost to mix in new soil and to use on top as a weed suppressant. It's surprising how soon it gets incorporated into the soil plus it's cheap! When you dig your first trench, see if there's any change in soil colour as you go down, because there's sometimes a definite line called a "hard pan" meaning this lower layer hasn't been disturbed, so you may have drainage problems if you don't break it up.

[hasbeans]

See if you can get hold of PAS 100 compost nearby.  It's often free or very cheap, will get you growing in the raised beds and you are using recycled food/garden waste rather than depleting ancient peat bogs.

[DHM]

Sounds like the plot I inherited in mid-May. If you have access to loads of compost, you could look into the no-dig concept; I'm on a tight budget so it's not for me but in theory it would work well on plain ground or raised beds. We opted against raised beds due to the faff of obtaining loads wood and having to build the things. Instead we went over all of ours with a fork, turning the soil to break it up and removing weeds, digging out taproots as we went. The plan now is to dump a load of manure on it in the autumn then spread the compost we do have from an old weedpile over the top before planting up. Harder work but in the longer term will make the soil more workable and give it a better texture

In terms of digging out a clay pan, I was advised against it due to the risk of bringing more clay to the surface and ending up with bigger problems in the long term. While digging out all your clay is said to improve drainage, others say with clay soil that is prone to drying out easily, the water retention might be a benefit, but it's a matter of opinion. On our plot, the pan is a thick layer with a ridge crossing it diagonally so to dig down and break all that up would be a major undertaking.

Good luck with yours!

[theplotbegins]

Thank you everyone. Lots to be thinking about. 
Off to take soil samples before deciding on best compost.....