Not every crop in Stardew Valley can be bought from Pierre's General Store, and there are a few seed types you can only find through non-traditional means. Some special crops like Sweet Gem ...

The new 1.6 update for Stardew ... Valley! The Carrot, Summer Squash, Broccoli, and Powdermelon can be found by foraging around Pelican Town. Plus, there are now two mystery giant crops to find.