As Florida prepares for a medical marijuana referendum, lawyers—smelling big profits— are scrambling to start niche practices advising marijuana dispensaries and growers and even open their own businesses.

Miami criminal defense attorney Jeffrey Feiler, past president of the Miami chapter of the Florida Association of Criminal Defense Lawyers, launched Grass Roots Marijuana Florida Inc. this month. He’s selling store franchises throughout the state, charging $25,000 for reservations and $75,000 for franchises.