Since everyone else has put their 2 cents in, I want to add mine!
Most of my soil is what is commonly called muck around here. A thousands of
years old swamp was dug into canals and the displaced "stuff" was piled up to
create buildable land. The "stuff" is very hard and very black, often shiney,
looks very similar to coal. I've been told the official term is clay. But
when I think of clay I think of the orange colored kind used on ball fields and
common Georgia soil. This post is based on the information that my soil is
clay.
When I first started digging up areas to plant, the digging was hard, very
hard. Often the shovel hit what felt like rocks, but upon inspection it was
really chunks of muck. At the beggining I didn't plant in beds, rather I just
stuck things in the ground where ever it pleased me. I did know I should
ammend the soil, so I always added lots of compost/manure to the planting
holes. But I admit the more holes I had to dig in a day, the smaller they
became.
The first plants were placed closer together over time and mulch was liberally
applied over the area to create beds. Now I can go into any bed and dig easily
even though the ammendments were not spread throughout the original soil. The
original muck, mulch and well ammended soil have slowly merged into a very
rich, moisture holding soil.
The backyard is different, it is mostly yellow sand. When the seawall was
added, the cheapest material available was aded as fill. That area is mostly
planted in beds. I used a tiller, added lots of manure, compost, and potting
soil. The beds have been covered with a deep layer of mulch. But if I dig
there I still find areas of nothing but yellow sand. The ammendments never
merged with the sand as they did with the muck.
Not even sure who I'm agreeing with here, but that has been my personal
experience with clay and sand.