Steam Weeds Away

The Greensteam 5000 machines are patrolling the streets of San Francisco, annihilating unwanted weeds using steam instead of herbicides. The City's Park and Rec Department recently purchased one for every Park Service Area. These high-tech gardening machines are the first of their kind in the United States. Each machine runs on a couple of gallons of water, a 12-volt battery, and a small propane tank.

The direct application of high-temperature stream ''explodes the cells'' of the offending plant, killing it down to its roots. The machines work well on sidewalk intruders surrounded by concrete. A set of solid wheels allows them to be easily carted around, and a brake prevents downhill runaways.