Due to rising public concern with the environmental impact of herbicides, non-chemical weed control techniques have increased in popularity.  Typical ‘organic’ crop production utilizes mechanical weed control, including soil cultivation, flaming, and hand-weeding, among other techniques.  However, these mechanisms are not applicable in turfgrass settings due to their destructive nature or high labor cost, leading many turfgrass managers with limited alternatives to herbicides.  The formation of a frost-like layer has been observed on plant tissue following liquid CO₂ applications.  Depending on the duration and severity of tissue freezing, prolonged exposure to liquid CO₂ may result in irreversible cellular destruction, interference of physiological processes, and eventual plant death.  Research was conducted in Raleigh, NC throughout 2010 to determine the efficacy of reclaimed liquid CO₂ for weed control in turfgrass systems.  Liquid CO₂ was applied utilizing a prototype handheld applicator equipped with an XR 8002 or XR 8004 nozzle calibrated to deliver 0.008 kg CO₂ m^-2sec^-1 or 0.016 kg m^-2 sec^-1, respectively.  Treatments included incremental liquid CO₂ exposure times (2-60 seconds) and comparative herbicide standards.  Common annual or perennial turf weed species, including annual bluegrass (Poa annua L.), buckhorn plantain (Plantago lanceolata L.), corn speedwell (Veronica arvensis L.), large crabgrass (Digitaria sanguinalis (L.) Scop.), smooth crabgrass (Digitaria ischaemum Schreb. ex Muhl.), goosegrass (Eleusine indica (L.) Gaertn.), Virginia buttonweed (Diodia virginiana L.), and white clover (Trifolium repens L.), were evaluated under greenhouse and/or field conditions.  Weed species were visually rated for control on a 0-100% scale (0=no visible plant injury; 100=complete plant death).  Results indicated greater weed control following prolonged exposure to liquid CO₂ applications.  Annual weed species were more susceptible to liquid CO₂ compared to perennial species; however, control varied depending on plant maturity.  Prototype modification reduced the LD₅₀ of crabgrass (1-3 tiller growth stage) from 14.8 to 2.6 seconds.  While no formal turfgrass tolerance studies have been conducted to date, observations indicate common bermudagrass (Cynodon dactylon (L.) Pers.) and tall fescue (Festuca arundinacea Schreb.) tolerance to liquid CO₂ applications.  These data suggest liquid CO₂ applications may provide an alternative to synthetic herbicides for control of select weeds in turfgrass systems.