Several winter canola cultivars have been selected for cold hardiness in north Alabama. Freeze injury sustained by canola plants generally depends on such factors as crop phenology, water content of plant tissues and the duration of freezing period. Canola is susceptible to frost damage at flowering and early pod stages, and prolonged freezing temperatures. Winter canola planted in Fall 2006 at the Alabama A&M University Winfred Thomas Agricultural Research Station, Meridianville, AL had reached these vulnerable stages when temperatures dropped below freezing for three consecutive nights in April 2007, resulting in severe plant damage including whole plant freeze burn, flower and early pod drops, seed abortion, and, ultimately, yield reduction. Higher number of plants on the outside borders of the plots incurred severe frost damage than centrally located plants within the experimental plots in the field. The severity of frost damage on canola also varied with size of experimental plots. The amount of frost damage were determined three to four weeks after freeze and compared among different sized canola plots (55 x 10 m², 30 x 5 m², 6 x 6 m² and 6 x 1 m²). Smaller plots sustained more damage as measured by the number of freeze-burnt plants, aborted flowers and pods, and seed yield.