Answer: Sweet cherries are self-fertile and do not require a pollinizer, with the exception of Bing, Stella, Royal Ann and Sunburst. These are self-sterile and are incompatible with each other so they require a different variety as a pollinizer. Your Van can rely on your Rainier for pollination. Your Rainier can rely on your Van. All sour cherries are self-fertile so you won't need to worry about fruit set.
Enjoy your cherries!
Q&A Library Searching Tips