In response to your question below, we kicked him out of the garden. It took some time, but he finally decided it wasn't worth it to tantrum. What had been up to 3 a day, is now 1 tantrum every 2 to 3 weeks. You are the greatest. I hope you aren't getting too big of an ego from all the people who sing your praises.
My son is 6 and has been MAJOR tantrumming for 2 1/2 years (until you entered my life). About a year ago, at my wits end, I went to a child psychologist (recommended by my pediatrician) who, after evaluating him (and seeing that he is obviously adopted as my son is a different race from us) determined that my son is throwing the tantrums because he is adopted. It doesn't matter that he was adopted as a very young baby, he still remembers the loss of his birth family and that is why he is throwing the tantrums when he doesn't get what he wants. We were told we would have to endure the tantrums, until he grows out of them (around age 16, we were told).
I thank God often that I have since found you!!