I am posting a new message on this subject as the last question made me curious. I Googled this and read that sand is not recommended as an addition to clay. I agree that clay + sand = concrete. That makes perfect sense. However, I have many years of dealing with poorly draining clay soil and do not agree that adding sand is a bad idea based on my own experience.

I am curious if anyone else has tried adding sand along with organic matter to clay?

I tried for years to add compost and other organic matter with disappointing results. It was only when I also added large amounts of sand that the much improved soil texture, drainage and remarkably better growing plants resulted. I do not have soggy soil in spring anymore or those horrible big dirt clods in summer. Large areas are now raised and the roots spread very fast and nicely in this 3 part mix. I can easily dig anywhere with just a hand trowel, even in summer. It makes common sense to me that adding anything that will break up the dense tight clay would be beneficial along with organic matter.

The grasses thrive in it and I can now grow types requiring perfect drainage in many areas.

Since I chose to go "no lawn" and do a native landscape, sand was economical. At its worst, our clay is red and slimy in spring and dries hard as rocks in summer while other "soils" are less horrible but still pretty bad with too much clay. Roots die of lack of oxygen. It forms big cracks and is nearly impossible to deeply water in summer. Are there different kinds of clay? You could make pottery with some of this stuff.