Odette Annable had only ever watched the Kentucky Derby on TV, but there was enough about Hallmark Channel’s new Louisville-set romance, Kentucky Roses , to convince her to sign on. “I didn’t know any of the backstory, how much of a community it is. I knew nothing going in,” she shared while stopping by DECIDER’s studio last month. “All I knew is that I loved the script, I love riding horses, I love the fashion and the whole story behind Churchill Downs and the Kentucky Derby, and Hallmark, of course.” Kentucky Roses marks Annable’s first Hallmark project, though she said she was set up for success after being teamed up with network mainstay Andrew Walker . “I couldn’t have had a better time. I was welcomed with warm arms,” she recalled. “I had Andrew Walker as my co-star, and he’s such a pro. He knows all the ins and outs. He knows the whole deal. So I felt very safe.…