In California, you can get that degree and work four years full time directly under a licensed landscape architect and then you would qualify for the exam. Landscape architecture licensing requires a degree from an accredited program and two years of working full time directly under a licensed landscape architect in most states (some allow several years working full time directly under a licensed landscape architect as an alternative). There is also three days of exams after that. There are only about 70 accredited programs.
These should help:
http://www.asla.org/nonmembers/educa...prog_alpha.htm
http://www.asla.org/Members/govtaffa...fornia2006.pdf