Paul got his start with houseplants, but they grew too fast, so he switched to cacti and succulents. While in grad school he started volunteering at the Botany greenhouse. That led to a half time job there. He quit for a few years to finish his dissertation and get a job outside academe. In 1999 he got the greenhouse job back and has been there since. He also works part time at the Indoor Sun Shoppe and has been a volunteer ½ day per week at Woodland Park Zoo with the Horticulture staff for 15 years.