Definition: Cold frames are unheated outdoor hardscape structures composed of a wooden or concrete framework and covered with glass or clear plastic. Cold frames are used for the process of hardening off seedlings; they can also serve the more general purposes of extending the growing season and sheltering plants from cold or frost. Although usually treated as utilitarian, there's no rule that says cold frames can't be designed so as to complement your landscape design!
Common Misspellings: coal frames
Examples:
The weather report warned of a possible frost, so I stuck my tender plants in the cold frame overnight.
