We're leaving today for two weeks in Argentina and Chile, where I hope to see some interesting gardens. I understand there is no tradition of open gardens in Argentina, so don't know what to expect. I hope to do a couple of posts from there, but that's uncertain.
Here is the web address of an innovative Uruguayan garden designer, Amalia Robredo, who I learned of through Noel Kingsbury's blog, and who specializes in use of plants native to the Uruguayan "monte" habitat and a sustainable design approach.
Amalia has been very helpful to me, providing historical and cultural context as well as contact information. You may want to take a look at the web site of the Argentinian garden magazine, Jardin, which has a gallery of garden images in a naturalistic style at this address.