Garbe was selected fifth overall by the Minnesota Twins in the 1999 amateur draft out of Moses Lake High School. He began his professional career that season, hitting .316 in 41 games for the Elizabethton Twins. That would be the only time he'd ever hit above .275 in a professional season.
Garbe split the 2003 season between the GCL Twins (eight games) and New Britain Rock Cats (66 games), hitting a combined .181. He began the 2004 season with the Rock Cats, hitting .201 in 114 games with them. On August 31, he was traded to the Seattle Mariners for Pat Borders. He spent three games in the Mariners organization that year, hitting .375 in nine at-bats with the San Antonio Missions. He hit .204 overall that year.