Everything is new in May and of course that also applies to Hearthstone and the ranked games. The May season has officially started and bears the title Garden party. That fits not only with spring, but also with Lunara, the new druid heroine who can be unlocked since the release of "The Witch Forest".
Hearthstone - 5 wins for the card back, 10 for Lunara
Only 10 wins in the ranking or in play mode against other players and you get the alternative druid:
“Lunara is the eldest daughter of Cenarius and a passionate defender of nature, but even the most powerful heroes need a place to relax. Spring always reigns in Lunara's secret refuge, no matter what time of year. She invites her friends there to relax, enjoy a cool breeze and bask in the comfortably warm rays of the sun. Be part of their garden party - and earn the back of the Lunara's Garden card - by joining in May Hearthstone plays! "
You get the card back of the season by winning 5 games in the ranking, it doesn't matter if it is 5 wins in wild or 5 wins in standard mode are. Then you will get the on June 1st at the end of the May season Card back in your reward chest.
“The loot from the reward chest for the Ranked Mode depends on your highest rank achieved in a Ranked Season. Reward Chests can contain Seasonal Card Backs, Arcane Dust, or Gold Cards and are awarded to you when you play Ranked Mode in Standard or Wild. Each season you ranked you will receive a chest that depends on your highest rank (regardless of the format). "
We wish you a lot of success!