Violet Thistlewaite Is Not a Villain Anymore by Emily Krempholtz

Guy Shadowfade is dead and Violet Thistlethwaite doesn't know what to do with herself. Having spent her life as the dark sorcerer's right hand, the powerful witch is now at loose ends. But she does know one thing: she doesn't want to be evil anymore. For once, she wants to sprout peonies instead of poison. The quaint town of Dragon's Rest, she decides, will be her second chance at life--a place where she can set down roots, open a flower shop, keep her sentient (and mildly homicidal) houseplant out of trouble, and quit dark magic after a lifetime of villainy. While Violet's vibrant bouquets and feats of plant magic soon charm the welcoming townsfolk, nothing she does seems to impress the prickly yet dashingly handsome Nathaniel Marsh, an alchemist sharing her greenhouse