STORY OF SEASONS: Pioneers of Olive Town

This will actually require you to plant and harvest growable flowers, rather than the ones you'll find throughout the farmland. If you need seeds, you can buy them from the flower shop Nguyen's Flowers (third row of houses, on the right before the ship plaza). You will want/need high-level flowers for Beekeeping later so it wouldn't hurt to start this early and save some seeds in a Seed Maker to repeat the process.

As with other progressive trophies, if you want to check your progress:

1) On the Title Screen, the trophy button will show you your progress for any trophies for the game.
2) In-game, on the Records page, interact with the Change Title button and choose Harvesting.