what can I do with realy bad clay in my garden which holds a lot of water when it rains
Lots of added compost which will help break it down a little over the years. I have used a mixture of mushroom compost and horse manure over the years just because the mushroom compost was very cheap (being got rid of from a local mushroom farm) and the horse manure is free from a local stables who are glad to see the back of it!
absalutley drench it ,wait until it drys and cracks ,absalutley drench ,wait until it drys and cracks..... it took me a good year to break it down,i dont think there is a quick way of acheiving this, but i won in the end and anything ive planted has grown.
My horrible clay soil has just become OK after a lot of additions of grit and organic matter. Each year I put on a mulch of compost and it does seem to help, the fine grit I have dug in to the soil. Good luck!
Several actions you can take, preferably doing all of them:
1. add lots of organic matter, such as well rotted manure. You will need a lot more than you will get from your compost heap. Not only is it a good fertilizer, but it also conditions your soil, which means it stops tiny clay particles from clagging together, which is important for drainage in winter and moisture retention in summer.
2. Add lots of sharp sand. Not builders sand, which has salts in it which can harm plants. This improves drainage and makes the soil more workable.
3. Add lime or gypsum. The chemistry is complicated, but this conditions the clay soil like organic matter, stopping clay particles from binding together. Lime will make your soil more alkaline, so if you don't want this then use gypsum, which has no effect on soil acidity. Buy builders plaster, which is practically 100% gypsum (except colouring) and is a lot cheaper than horticultural gypsum.
You can get sharo sand and plaster from your local merchant. And whatever amount of manure, sand and gypsum you think you are going to need, treble it!! You can't add enough, and its a lot harder to work in more after you have planted up.
I used a rough ratio of 6:3:1 manure, sand and gypsum. I have found a local horselover who collects horse manure from her paddock by hand (gloved!) so no straw - 50p a large bag!!!!!.
Compost, compost and more compost. In the wettest part of my garden I now have a natural clay pond but in other areas I dump all my homemade compost on it and lots of wood chip as a mulch which I get from a local tree surgeon. I have never dug any of it in, just left it for the worms to sort out. Within a year my soil was nice in the top 15cm and now having been doing this for 6 years I have to go down at least 60cm to find solid clay. You will need to do this or at least top it up each year. The other thing to do is when planting in it, dig a hole at least twice as wide as needed and replace the clay dug out with compost and homemade compost and grit. The plants roots are then more likely to spread out rather than go round and round.
We moved into our new home 2 years ago and it has very heavy clay, which had not had much mulching. We started straight away digging in compost and placing a good mulch of wood chips on the surface. Improvements are slight but noticeable, I am expecting to have a reasonable tilth in about 4 years of continual improving.