Gardenscapes-Level 77 is a bit tough, but is indeed beatable. The strategy for solving it can be divided into two steps:
1. Clearing the main field. That shouldn’t be a problem since a lot of automatches are created through portals at the bottom of the field. Clear the pieces below the lemonades and near them to move them to the edges of the field.
2. Clearing the exit points. Melt the iced pieces and eliminate acorns on the sides of the field. By the time lemonades reach the last portals, it’s best to free the exit points from ice. The easiest way to do that is with Rainbow Blast, but if possible you can use bombs too.
Remember not to blow the pieces the second time before lemonadesreach the last portal, because new pieces will replace the old ones and the lemonadeswon’t move. Also, don’t forget to explode power-ups together to get the Rainbow Blast faster, as it can help you beat the level.