You typically get a lot of Flowers in the early game of Forager, but they can actually because very scarce in the late game, since there's no straight forward way to grind out a huge number of them. The only thing is that there is a method to grinding them, and you are just about to find out how you can set up a Flower grind in Forager.
You will need to have the Necro Rod found at the end of the Skull Maze, sine this allows you to spawn Skeletons and Skeleton Warriors. Spawn enemies then switch to a sword (needs to be Druid Sword or better), because killing enemies with the sword will make them drop Flowers.
To make this as efficient as possible, do this on an island that is surrounded by Lighthouses, since these will stack and give you a huge amount of Flowers in a very short time.
This method also gives you a lot of Bones, which can be a nice way to get some extra Coins by selling them at the Market.