Dear Friends, it seems to me there is a lot of comparison between Apples and Oranges going on here. "Frost- the er, white frosty stuff, is a physical result of a combination of temperature (air and surface) as well as humidity and barometric pressure (altitude). It is not a specific temperature. Freeze - is the empirical standard temperature where water freezes- i.e. 32 F or 0 C. Cold Damage - can occur in plants depending on a wide variety of factors unrelated to frost or freeze. Experience from many growers suggest that there are a few specific temperature thresholds: 50 F. some extremely sensitive tropical plants such as Sansevieria, some orchids etc show definite signs of damage at temperatures around here or less. Leaves can show necrotic spots and discoloration below 50 F. 32 F There obvious damage due to freezing of water crystal in succulent foliage. Leaves collapse and desiccate. 25 - 27 F - a commonly low temperature for some marginally hardy plants. Able to be unaffected by freezing temperatures, but just barely. 15 F or so for another group of slightly hardier plants. The observant may see some relationship with Hardiness Zones in 10 degree increments. I think growers with a wide experience in different climates and keen observation skills will see that some plants can simply tolerate more or less heat/cold than others. Just a suggestion. Jim W. -- Dr. James W. Waddick 8871 NW Brostrom Rd. Kansas City Missouri 64152-2711 USA Ph. 816-746-1949 Zone 5 Record low -23F Summer 100F +