Gardenscapes-Level 25 is the first real challenge in the game. To beat it, you will need to have more space for action on the field first and only then start collecting the gnomes.
1. Eliminate the crates at the sides of the field as soon as possible, then start clearing the bottom of the field from the chains.It is important to focus on the entire field, not just one side. Try to create or free the Rainbow blasts, but for maximum efficiency be sure to use them after you’ve cleared the field completely.
2. After clearing the field from obstacles you will have a large number of automatches as well as power-ups, greatly accelerating the collection of gnomes. Don’t forget about the gnomes hidden under the crates in the center of the field – they should be collected last with the automatches and power-ups accumulated to allow you spend fewer moves.