Power Berries are red fruits found during game that increase your stamina. These are valuable items, so get them whenever you have the chance.
1. In the Winter, smash the boulder on the frozen pond near the Fisherman's tent with your Golden Hammer.
2. If you spend enough time tilling your land, you'll dig up one.
3. You can dig one up in the mine during the Winter.
4. While at full strength, throw a vegetable in the Harvest Goddess's pond and wish for strength.
5. Give the Shady Salesman 1000 G at the Flower Festival.
6. Win the Egg Festival.
7. Fish off the dock at the Beach during the Winter. You might catch one.
8. Throw a large fish into the pond near the Fisherman's tent between 9:00 and 5:00.
9. Give a Marble to the Harvest Sprites. See Secrets on how to get the Marble.
10. Befriend Basil. He may give you one.