She was so tired of the cold! That was all it could do any more—make her tired. Year after year, she felt sure that she would die before the cold was over. Now, according to the Almanac, it was spring…. But year after year it was always the same. The plants would be set out in their frames, transplanted always too soon, and there was a freeze…. When was the last time they had grown tall and full, that the cold had held off and there was a crop. 

请问专家，When was the last time they had grown tall and full, that the cold had held off and there was a crop.这句话中的that the cold had held off 做什么成分?