Here is Kevin Brandt’s reply to my email about a definitive answer to pollinators of the Nadia (Cherry-Plum):
There are actually 4 definitive answers to your question. They are:
· Black Amber
· Anne Gold
This information is based off of genetic testing performed by our partners in France and is very specific to these 4 selections. We too have struggled with pollinizers outside of these and are currently using Black Amber with good results. Attached is a picture of fruit off our test trees in the Yakima valley with very good results.
Nadia (now trademarked as Branchberry®) is a fickle variety to pollinate, but with the right pollinizers and an abundance of bloom, the possibilities are there. The selections is very good for the home grower as the true flavor of the selection develops from tree ripened fruit. Fruit harvested too early and allowed to ripen off of the tree never truly reaches its full flavor profile. My kids love the selection and look forward to the fruit every year. I am hopeful that you will too.
Please let me know if I can assist further. Good luck and enjoy.