Mexican farmers are feeding a growing addiction in the U.S., where heroin use has spread from back alleys to the cul-de-sacs of suburbia. The heroin trade is a losing prospect for everyone except the Mexican cartels, who have found a new way to make money in the face of falling cocaine consumption and marijuana legalization in the United States. Once smaller-scale producers of low-grade black tar, Mexican drug traffickers are now refining opium paste into high-grade white heroin and flooding the world’s largest market for illegal drugs. According to the DEA’s 2014 National Drug Threat Assessment, Mexico produces nearly half of the heroin found in the United States, up from 39 percent in 2008. When the poppy plants finish flowering about three months into the winter growing season, a farmer armed with a razor-sharp, thumb-scorer and a metal scraping pan can collect 300 grams of opium paste, worth more than $275, in a single day.