Annual morningglory is increasing in California cotton, and growers have considerable difficulty once it is present. Yet long-term experience by growers who have had it for over 20 years shows that timely cultivations after each irrigation until layby in mid-July, using specialty tools such as the Texas rod weeder, a tine weeder, or Bezzerides row weeders, will prevent cotton yield loss from later emerging plants. Where cotton stands are skippy or where rows do not close due to short cotton, the layby use of herbicides is indicated. Kill of twining ivyleaf morningglory in cotton seems impossible with presently registered herbicides. At layby control seems more reliable if morningglory is emerged and then sprayed with residuals such as oxyfluorfen (Goal), prometryn (Caparot) or cyanazine (Bladex) plus surfactant.