Anything with loads of humus, like a spent mushroom compost, and some grit or sand to improve drainage I would say Paul.

Hi Karen lol its mark?

Thankyou so much for answering my query .Drainage seems to be the most important thing grit/building grade ,i have not heard of mushroom compost .Since this post i have looked into a soil improver for clay soil.Thankyou again mark

Sorry Mark...brain fog!

leaf litter is a good one too. as it has lots of nutrients as well as humus and beneficial micro-organisms.

Once the organic matter is added, dropping in some earthworms from the bait shop will help keep it turned and aerated naturally over the years. Actually, you will likely get a good earthworm population eventually, if you just wait, but adding some in speeds the process. I would also put a top dressing of 3-5 cm of composted material--manure, crop waste, leaf mould, home made, etc.--every spring, to maintain the levels of organic matter in the soil.

Hi all thankyou all so much for the great information.Unfortunately i am going to use a manmade soil improver for this year will do my own compost heap for next year.:)))))

Cannot believe i have given loads to the council instead of storing it up der me