This event is available for all players that have completed Ricardo's house (the third chapter of the main story). "Beanstalk" event starts on Thursday every week and lasts 48 hours from the moment you have started it.
During this event you can win rewards, including boosters for the match-3 levels and even infinite lives for a fixed amount of time. To receive them you need to win match-3 levels.
Once the event is started, you will see your current progress in the starting window of each match-3 level. For each level you win, the beanstalk grows up. There are certain points on which you receive scaling rewards.