Q.Can the variety of a blueberry bush be visually determined?
I have a blueberry bush that I found out was planted about 17-18 years ago. I want to expand the patch with additional bushes. If I knew the variety, I could plant varieties to expand the harvest season, provide superior pollination, and select other varieties with a broader range of bush size and berry taste characteristics. How do I determine the variety that I have?

It can be very difficult to pinpoint the exact cultivar, but you could pinpoint the exact species that it is. You may have to watch it over a few seasons to see when it flowers, the color, and other characteristics about it to determine what species it is using a blueberry dichotomous key. These can be found many places online. You can also take a sample, or pictures to your local extension service, and they may be able to help. This link will help you find the closest one to you: https://www.gardeningknowhow.com/extension-search/