21 Moves (revised)
The spider has several empty nests to jump into, so attack him first, but take any opportunities to start opening the flowers, or gathering any higher points crops.
Remember you can use a shovel to break webs or open flowers.
Once the nests on the left side have been broken and he moves to the right, you can also use the spaces where the nests were on the left to get to him if the crops fall in the right places too.
Make as long a row as you possibly can when making matches for extra points.The more points mean the more stars and the more animals are unlocked. More animals means more free boosters unlocked :)