Many of the older cherry varieties are self unfruitful; they produce viable pollen but are not always compatible with all varieties. Many sweet cherry groups are cross-incompatible. Varieties within a group should not be planted together without a suitable pollinizer. Below are some of the more common cross-incompatible groupings of the varieties recommended in this guide, as well as some commonly advertised in nursery catalogs. The Roman numeral indicates the classification group used by breeders.
I. Bing, Lambert, Napoleon, Emperor Francis
VI. Stark's Gold, Hartland
IX. Van, Venus, Windsor
X. Gold, Viva, Vogue
XI. Hedelfingen, Vic, Ulster
XII. Hudson, Schmidt, Rainier, Viscount
XIII. Seneca, Vega, Vista