I've always heard not to add sand to clay.
That's how bricks are made. :(

Now, sprinkling green sand on a lawn to improve soil we've done, seemed to help.

Expanded shale works better, it helps to break up the clay and add air to the soil.

Your soil needs organic material. Any horse lots around?
It's OK if some sand is mixed in with the organic material (compost). Dig as deeply as you can in your garden, turning the soil upside down, add the amended soil, then till the heck out of it. Or sometimes all that I can muster is just to turn it with a shovel a time or two.

Happy gardening

Thank you all. Compost and expanded shale. And, so maybe, if you have a dry laid sidewalk underlain with sand, that's been there for 30 years, maybe you wouldn't have to try and get the sand out of the local soil if you take up the sidewalk to turn it into a garden bed.

I have added course sand and it helps. Clay will get as hard as a brick wither you add sand or not. Bricks are not made by adding sand.
Peat moss lasts much longer than compost or other organic matter but is fairy inert as to adding nutrients. It also is acidic which helps with alkaline clays.
Perlite works well if can stand soil full of little white dots.

Yes, many cultures certainly do make bricks by adding sand to clay. Then they do other things to it (drying and firing) to make bricks.

Peat Moss isn't highly recommended either, at least for my area. It holds moisture and clay doesn't need that either.
Peat moss is already pretty broken down so there is no 'activity' by the worms which is what makes the soil better.
When I researched this years ago, the easiest/best thing for my situation was to compost in place. Let mother nature do the heavy lifting for you.

I'd bury my kitchen scraps right in the beds. By next year that area was wonderful soil. You can re make your soil one bucket or shovel full at a time. Or try other larger scale methods.

Spots where I placed the compost bin turned into wonderful soil. Places where I piled grass clippings and leaves turned wonderful soil over the next year all by themselves. I didn't have to dig, or turn the soil or work anything in.

Eventually I spent one early spring season adding horse stall cleanings and composted horse manure on top of all my beds piling it right on top of my mulch. It worked wonders for the established plants and the soil.

I think adding sand to dense clay is good when balanced by adding compost. I think when in doubt compost. When I lived on clay, I added compost anytime I worked the garden. The minerals in sand are good to add . Greensand is good, lava sand is good. Expandable shale is good . CactusGarden, who has OK thick clay added a whole lot of sand to grow her cactus garden and she found that it improved her soil for many other things also. Some people say to add a rough bark mulch but then one has to wait a year to grow anything. It adds STRUCTURE to the soil and the bugs do a lot of the work of distributing the good stuff around. I have also heard that putting down 4 inches of much/compost and letting it decompose will get the bugs bringing thew good stuff down into the soil. I have not tried this but I might do it this year in an area of clay that I have on the west side of my wood shop.

I had very good results where I added it. I can't find many fans out there, mostly objectors, but for me it was the difference between chicken soup and chicken s--t. My soil was clay loam that made dirt clods when dry, was hard to water deeply and mud when wet. Now its sandy loam, fast draining, holds water, easy to water deeply and easy to dig. I wouldn't do this with very heavy clay. I would dig clay out or add soil on top, if its anything like some of the sticky stuff I have seen elsewhere or what I have if you go down deep enough.

One thing someone posted on this subject once was that sand can cause nematodes. I'm not growing vegetables and I don't notice anything like that but I did look it up and read that elsewhere also.

"Peat Moss isn't highly recommended either, at least for my area. It holds moisture and clay doesn't need that either.
Peat moss is already pretty broken down so there is no 'activity' by the worms which is what makes the soil better."

Yes peat moss holds moisture but so does compost.
Yes as i said peat moss is fairly inert. I can tell you that since I added it I have worms like I have never had before. Peat moss is not mixed to add nutrition but to break down the clay structure for a longer period of time than compost. Peat Moss helps with the CEC (cation exchange capacity)of clay soils. Peat moss is beneficial to compost. I did a search for something that agreed with the do not add peat moss to clay soils and found nothing. If you could give me a link to something I would appreciate it.
Sand; You are right I should have said screened course sand. Unscreened sand with varying sizes of grains will bind together.
I am in no way saying anything negative about using compost.
below is a link to some info.

Here is a link that might be useful: Peat Moss, Coir Fibre and Compost:

Well, for me, it's simply donkey manure, and I have wonderful soil.

Merry,
It wouldn't be a waste of time to read through this thread linked below.

It even lists a local source for horse manure!

Here is a link that might be useful: Soil amendment for high pH, sun burned Texas