Yggdrasil wood is one of the new resources you can find in the new Valheim Mistlands (opens in new tab) update. The roots of the world tree, Yggdrasil are accessible in the mysterious new biome, along with its smaller shoots, but it's not immediately clear how to gather this new crafting material.
The Mistlands update offers far more than the new biome to explore. You can create new crafting stations, and make new weapons and armor—you can even be a necromancer (opens in new tab). If you're looking to start with the more basic of the Mistlands' resources though, here's how to find and gather Yggdrasil wood in Valheim.
Valheim Yggdrasil wood: How to find and gather it
You might think that there's an abundance of Yggdrasil wood just there for the taking in the Mistlands but sadly not all the wood you see can be chopped for its resource. Yggdrasil wood is harvested from Yggdrasil shoots, which are much smaller than the big roots all over the Mistlands. Ancient roots, to give the latter its correct name, cannot be harvested for Yggdrasil wood at all and are instead used for their sap which is then turned into Eitr (opens in new tab).
Yggdrasil shoots resemble the tree saplings you can find in the Meadows, though they can grow much larger, looking more like spindly trees. Looks can be deceiving though and they're made of stern stuff—basically, you'll need a black metal axe to chop them. Black metal is one of the Plains resources, so you should have plenty handy if you feel you're ready to venture into the Mistlands. And if not, I guess it's time to raid those Fuling villages.
Just like other types of wood, only a small percentage of what you harvest from Yggdrasil shoots will be of higher quality, so you might need to find quite a few to get a decent yield of Yggdrasil wood.