Frost kills kudzu foliage, and kudzu is rare or sparse in climates with freezing temperatures. Would freezing the crown kill the kudzu plant? In these experiments freezing is tested as a possible treatment. The freezing treatment was tested in cases where a portion of the crown was visible to give the treatment a better chance of working: It is difficult enough trying to freeze something in the open air on a hot summer day, let alone freeze something that is buried below asphalt or concrete!
This photograph shows a handheld medical device charged with liquid nitrogen applying a stream of very cold gas to a kudzu crown (circled in red) embedded in a crack in asphalt. Note the glove used to protect the hand! The crown is not removable without breaking open asphalt, hence the attempt to kill it by freezing. The device is similar in function to an aerosol can, with a trigger and nozzle. Dermatologists use these bottles to freeze pre-cancerous cells. Dr. Elizabeth Dunlavey, Spartanburg Dermatology & Skin Surgery Clinic, graciously provided the bottle and refills for us. All photographs May 2006.
Here is a closeup of the freezing procedure for a different crown, circled in red, in asphalt. Different treatment times are part of the experimental protocol, as it is difficult to know to what depth the crown is frozen. The results of these experiments were not promising. Perhaps this is not surprising because kudzu is found in northern states where below-freezing winter temperatures are common.
Freezing: The Bottom Line