From ASLA’s website:
Eligibility Requirements – Initial Licensure
Requirements: To qualify for the written examination, applicants must have six years of training and educational experience in actual practice of landscape architecture. A degree from a school of landscape architecture approved by the board is deemed equivalent to four years of training and educational experience. [A degree in landscape architecture from a non-approved school is deemed equivalent to three years training and educational experience. An extension certificate in landscape architecture from an approved school is equivalent to two years training and educational experience. An associate degree in landscape architecture from a city/community college (with two-year curriculum) is deemed equivalent to one year of training and educational experience. All candidates must have had one year education credit and two years experience credit to take the exam. Candidates must also pass the California supplemental exam.]
The words “actual practice of landscape architecture” seem to negate the possibility of using contractor experience.
