you don‘t get special buffs from eating local/seasonal produce in its biome. Nearly all cultivated plants today are the result of extensive selective breeding and globalization, they weren‘t just put on earth like this.
The farther you go to the poles the more any plant is affected by changing daylight hours during the year, which caused them to evolve seasonality. Around the world people just figured out what to plant when to sustain themselves.
eg here you would traditionally harvest hardy stuff like carrots, beets and any cabbage in late fall to last over the winter with your stored grain from summer.