Blackberries are in fact kosher for Passover, as they are not against the series of dietary laws which those who practice Judaism must abide by according to their faith.
There are many Jewish people who have blueberry dishes for this celebration and you can too. The internet is filled with different blueberry Passover recipes, so you will be able to explore what some of your options are. There are a number of blueberry dishes that will make a great dessert for this holiday.
Those who are concerned that blueberry dishes might not be kosher will not be able to rest easy knowing they can have this fruit.