Originally posted by J-&Dre:

Originally posted by muffins:

What biome are you planting them in? Most crops are biome sensitive. The meadows will grow carrots and turnips, while the plains will grow flax and wheat.

I am planting them in a meadow in a cultivated field. But that doesn't make any sense though, as the carrot seeds i gathered is from Black Forrest.

Edit: Some people suggested it is because it needs a workbench. This seems to be true. I finally harvested both seeds and carrots now. Weird that you actually need workbench for that. Looks weird with a table standing in a field.

Any base zone object will do. They just need to be in the 20m base zone. Stops them despawning/enemies spawning on them. ( https://valheim.fandom.com/wiki/Player_base )
Make a small tool shed.
Carrots can grow anywhere cultivated. Turnips anywhere but mountains. Flax and Barley Plains only.