Such great info here! Thanks dice, for your thoughts on the cement block issue.
I have only tried amending the 'soil' here once, and without a jackhammer and simply taking the clay away, it is impossible to garden in it. This is the stuff the Spanish made presidio walls out of, for goodness sake! Since I am in a different home this year, I am starting over with new beds, new soil, etc. This thread has been very helpful with ideas!
~Thalia