City ordinance 9.16 states that weeds and grass shall be kept at a maximum height of six inches. After clearing weeds or trimming the lawn, immediately dispose of all clippings to prevent the spread of noxious weeds and to avoid attracting mice, rats, and other vermin.
The property owner is also responsible for maintaining the land between the property line and the street (park strip). Landscaping shall be maintained free of overgrown, dead, diseased, or other hazardous trees and vegetation, and shall be maintained in an aesthetically pleasing fashion. Salt Lake City encourages landscaping with plants that require less watering.
For more information about weeds and clearing of property regulations, see The City Code, Title 9.16