A Touch of Darkness (Hades & Persephone, Book #1) by Scarlett St. Clair
Persephone is the Goddess of Spring by title only. The truth is, since she was a little girl, flowers have shriveled at her touch. After moving to New Athens, she hopes to lead an unassuming life disguised as a mortal journalist. Hades, God of the Dead, has built a gambling empire in the mortal world and his favorite bets are rumored to be impossible.
After a chance encounter with Hades, Persephone finds herself in a contract with the God of the Dead and the terms are impossible: Persephone must create life in the Underworld or lose her freedom forever. The bet does more than expose Persephone's failure as a goddess, however. As she struggles to sow the seeds of her freedom, love for the God of the Dead grows-and it's forbidden.