During 1987-1989 four trials were conducted in Middlesex and Huron Counties, in southwestern Ontario to study the effect of cereal crop species (rye, barley, oats) and method of planting on the growth and yield of no till planted corn. The methods of planting included broadcasting the seed at soybean leaf drop, broadcasting the seed at soybean harvest, tilling the soil and drilling the seed into soybean residue and a control where no seed was planted. Excess rainfall during the fall of 1987 and l988 and drought during late spring of 1988 affected the performance of the cover crops and main (corn) crop. Results from two years of study indicate that winter rye, spring barley and spring oats seeded at soybean leaf drop or at harvest increased soil residue cover when compared to soybean stubble alone, through winter and early spring. Barley and to a lesser degree, oats, seeded at harvest followed by seeding at leaf drop achieved the best corn growth and yield. Practical considerations related to labour needs, weather and the timing of cover crop establishment for adequate fall growth do not favour the planting of cereal cover crops at or after harvest.