Double Growing Dirt usually occupies several tiles on the board, making it difficult for similarly colored Jellys to group together. Eliminate Jellys next to them or use explosive obstacles (e.g. Living Stones) twice in order to pop them.     

Watch out! These two-eyed creatures multiply and engulf adjacent Jellys if you don't eliminate Jellys next to them with each move.

Tip: Use 2 Water Splash boosters to clear a Growing Dirt.