Most cherry varieties have a chilling requirement of 800 or more hours, meaning that in order to break dormancy, blossom, and set fruit, the winter season needs to have at least 800 hours where the temperature is below . “Low chill” varieties requiring 300 hours or less are Minnie Royal and Royal Lee, requiring cross-pollinization, whereas the cultivar, Royal Crimson, is self-fertile. These varieties extend the range of cultivation of cherries to the mild winter areas of southern US. This is a boon to California producers of sweet cherries, as California is the second largest producer of sweet cherries in the US.