Plants growing in a row of cold frames.
cold frame definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
an unheated, boxlike, glass-covered structure for protecting young plants outdoors
cold frame definition by American Heritage Dictionary
An unheated outdoor structure consisting of a wooden or concrete frame and a top of glass or clear plastic, used for protecting and acclimatizing seedlings and plants.